diff --git a/docs/source/examples/gen_examples.py b/docs/source/examples/gen_examples.py
index 922c5c569..2ae1a1b5a 100755
--- a/docs/source/examples/gen_examples.py
+++ b/docs/source/examples/gen_examples.py
@@ -139,7 +139,7 @@ def _gen_demonstrated_funcs(example_config_path: Path) -> dict:
     )
     if dataset_name in all_demonstrated:
         logger.warning(
-            f"Duplicate dataset name {test_dataset_name} -> {dataset_name}, " "skipping"
+            f"Duplicate dataset name {test_dataset_name} -> {dataset_name}, skipping"
         )
         continue
     del test_dataset_options, test_dataset_name
diff --git a/docs/source/v1.8.md.inc b/docs/source/v1.8.md.inc
index f9f583fb9..7f100c583 100644
--- a/docs/source/v1.8.md.inc
+++ b/docs/source/v1.8.md.inc
@@ -14,9 +14,9 @@
 
 [//]: # (- Whatever (#000 by @whoever))
 
-[//]: # (### :bug: Bug fixes)
+### :bug: Bug fixes
 
-[//]: # (- Whatever (#000 by @whoever))
+- Fix bug where Maxwell filtered data was not handled properly in CSP (#890 by @larsoner)
 
 ### :medical_symbol: Code health
 
diff --git a/mne_bids_pipeline/_config_import.py b/mne_bids_pipeline/_config_import.py
index 25eea4b36..98286d4ba 100644
--- a/mne_bids_pipeline/_config_import.py
+++ b/mne_bids_pipeline/_config_import.py
@@ -434,7 +434,7 @@ def _check_misspellings_removals(
         if user_name not in valid_names:
             # find the closest match
             closest_match = difflib.get_close_matches(user_name, valid_names, n=1)
-            msg = f"Found a variable named {repr(user_name)} in your custom " "config,"
+            msg = f"Found a variable named {repr(user_name)} in your custom config,"
             if closest_match and closest_match[0] not in user_names:
                 this_msg = (
                     f"{msg} did you mean {repr(closest_match[0])}? "
diff --git a/mne_bids_pipeline/_config_utils.py b/mne_bids_pipeline/_config_utils.py
index 701cd93a3..d6bcb0ce5 100644
--- a/mne_bids_pipeline/_config_utils.py
+++ b/mne_bids_pipeline/_config_utils.py
@@ -403,7 +403,7 @@ def get_mf_ctc_fname(
             root=config.bids_root,
         ).meg_crosstalk_fpath
         if mf_ctc_fpath is None:
-            raise ValueError("Could not find Maxwell Filter cross-talk " "file.")
+            raise ValueError("Could not find Maxwell Filter cross-talk file.")
     else:
         mf_ctc_fpath = pathlib.Path(config.mf_ctc_fname).expanduser().absolute()
         if not mf_ctc_fpath.exists():
diff --git a/mne_bids_pipeline/_import_data.py b/mne_bids_pipeline/_import_data.py
index c3c319f44..5511be548 100644
--- a/mne_bids_pipeline/_import_data.py
+++ b/mne_bids_pipeline/_import_data.py
@@ -16,7 +16,7 @@
     get_runs,
     get_task,
 )
-from ._io import _empty_room_match_path, _read_json
+from ._io import _read_json
 from ._logging import gen_log_kwargs, logger
 from ._run import _update_for_splits
 from .typing import PathLike
@@ -403,6 +403,7 @@ def import_experimental_data(
         _fix_stim_artifact_func(cfg=cfg, raw=raw)
 
     if bids_path_bads_in is not None:
+        run = "rest" if data_is_rest else run  # improve logging
         bads = _read_bads_tsv(cfg=cfg, bids_path_bads=bids_path_bads_in)
         msg = f"Marking {len(bads)} channel{_pl(bads)} as bad."
         logger.info(**gen_log_kwargs(message=msg))
@@ -701,6 +702,12 @@ def _get_mf_reference_run_path(
     )
 
 
+def _empty_room_match_path(run_path: BIDSPath, cfg: SimpleNamespace) -> BIDSPath:
+    return run_path.copy().update(
+        extension=".json", suffix="emptyroommatch", root=cfg.deriv_root
+    )
+
+
 def _path_dict(
     *,
     cfg: SimpleNamespace,
@@ -725,20 +732,6 @@ def _path_dict(
     return in_files
 
 
-def _auto_scores_path(
-    *,
-    cfg: SimpleNamespace,
-    bids_path_in: BIDSPath,
-) -> BIDSPath:
-    return bids_path_in.copy().update(
-        suffix="scores",
-        extension=".json",
-        root=cfg.deriv_root,
-        split=None,
-        check=False,
-    )
-
-
 def _bads_path(
     *,
     cfg: SimpleNamespace,
diff --git a/mne_bids_pipeline/_io.py b/mne_bids_pipeline/_io.py
index f1a2b0ce3..dc894cb6b 100644
--- a/mne_bids_pipeline/_io.py
+++ b/mne_bids_pipeline/_io.py
@@ -1,9 +1,6 @@
 """I/O helpers."""
 
-from types import SimpleNamespace
-
 import json_tricks
-from mne_bids import BIDSPath
 
 from .typing import PathLike
 
@@ -16,9 +13,3 @@ def _write_json(fname: PathLike, data: dict) -> None:
 def _read_json(fname: PathLike) -> dict:
     with open(fname, encoding="utf-8") as f:
         return json_tricks.load(f)
-
-
-def _empty_room_match_path(run_path: BIDSPath, cfg: SimpleNamespace) -> BIDSPath:
-    return run_path.copy().update(
-        extension=".json", suffix="emptyroommatch", root=cfg.deriv_root
-    )
diff --git a/mne_bids_pipeline/_run.py b/mne_bids_pipeline/_run.py
index 73e4c6082..8f3ace7ab 100644
--- a/mne_bids_pipeline/_run.py
+++ b/mne_bids_pipeline/_run.py
@@ -67,13 +67,13 @@ def __mne_bids_pipeline_failsafe_wrapper__(*args, **kwargs):
                 # Find the limit / step where the error occurred
                 step_dir = pathlib.Path(__file__).parent / "steps"
                 tb = traceback.extract_tb(e.__traceback__)
-                for fi, frame in enumerate(inspect.stack()):
+                for fi, frame in enumerate(tb):
                     is_step = pathlib.Path(frame.filename).parent.parent == step_dir
                     del frame
                     if is_step:
                         # omit everything before the "step" dir, which will
                         # generally be stuff from this file and joblib
-                        tb = tb[-fi:]
+                        tb = tb[fi:]
                         break
                 tb = "".join(traceback.format_list(tb))
 
@@ -221,9 +221,7 @@ def wrapper(*args, **kwargs):
                     for key, (fname, this_hash) in out_files_hashes.items():
                         fname = pathlib.Path(fname)
                         if not fname.exists():
-                            msg = (
-                                f"Output file missing {str(fname)}, " "will recompute …"
-                            )
+                            msg = f"Output file missing {str(fname)}, will recompute …"
                             emoji = "🧩"
                             bad_out_files = True
                             break
@@ -231,7 +229,8 @@ def wrapper(*args, **kwargs):
                         if this_hash != got_hash:
                             msg = (
                                 f"Output file {self.memory_file_method} mismatch for "
-                                f"{str(fname)}, will recompute …"
+                                f"{str(fname)} ({this_hash} != {got_hash}), will "
+                                "recompute …"
                             )
                             emoji = "🚫"
                             bad_out_files = True
diff --git a/mne_bids_pipeline/steps/init/_02_find_empty_room.py b/mne_bids_pipeline/steps/init/_02_find_empty_room.py
index fcb0536c5..d56318365 100644
--- a/mne_bids_pipeline/steps/init/_02_find_empty_room.py
+++ b/mne_bids_pipeline/steps/init/_02_find_empty_room.py
@@ -13,7 +13,8 @@
     get_sessions,
     get_subjects,
 )
-from ..._io import _empty_room_match_path, _write_json
+from ..._import_data import _empty_room_match_path
+from ..._io import _write_json
 from ..._logging import gen_log_kwargs, logger
 from ..._run import _prep_out_files, _update_for_splits, failsafe_run, save_logs
 
diff --git a/mne_bids_pipeline/steps/preprocessing/_01_data_quality.py b/mne_bids_pipeline/steps/preprocessing/_01_data_quality.py
index c12dd6a26..479deabe8 100644
--- a/mne_bids_pipeline/steps/preprocessing/_01_data_quality.py
+++ b/mne_bids_pipeline/steps/preprocessing/_01_data_quality.py
@@ -17,7 +17,6 @@
     get_subjects,
 )
 from ..._import_data import (
-    _auto_scores_path,
     _bads_path,
     _get_mf_reference_run_path,
     _get_run_rest_noise_path,
@@ -159,7 +158,7 @@ def _find_bads_maxwell(
     elif cfg.find_noisy_channels_meg and not cfg.find_flat_channels_meg:
         msg = "Finding noisy channels using Maxwell filtering."
     else:
-        msg = "Finding flat channels and noisy channels using " "Maxwell filtering."
+        msg = "Finding flat channels and noisy channels using Maxwell filtering."
     logger.info(**gen_log_kwargs(message=msg))
 
     if run is None and task == "noise":
@@ -232,9 +231,12 @@ def _find_bads_maxwell(
     logger.info(**gen_log_kwargs(message=msg))
 
     if cfg.find_noisy_channels_meg:
-        out_files["auto_scores"] = _auto_scores_path(
-            cfg=cfg,
-            bids_path_in=bids_path_in,
+        out_files["auto_scores"] = bids_path_in.copy().update(
+            suffix="scores",
+            extension=".json",
+            root=cfg.deriv_root,
+            split=None,
+            check=False,
         )
         if not out_files["auto_scores"].fpath.parent.exists():
             out_files["auto_scores"].fpath.parent.mkdir(parents=True)
diff --git a/mne_bids_pipeline/steps/sensor/_05_decoding_csp.py b/mne_bids_pipeline/steps/sensor/_05_decoding_csp.py
index 9b93c0c32..8549157bd 100644
--- a/mne_bids_pipeline/steps/sensor/_05_decoding_csp.py
+++ b/mne_bids_pipeline/steps/sensor/_05_decoding_csp.py
@@ -79,21 +79,15 @@ def prepare_epochs_and_y(
     *, epochs: mne.BaseEpochs, contrast: tuple[str, str], cfg, fmin: float, fmax: float
 ) -> tuple[mne.BaseEpochs, np.ndarray]:
     """Band-pass between, sub-select the desired epochs, and prepare y."""
-    epochs_filt = epochs.copy().pick(["meg", "eeg"])
-
-    # We only take mag to speed up computation
-    # because the information is redundant between grad and mag
-    if cfg.datatype == "meg" and cfg.use_maxwell_filter:
-        epochs_filt.pick("mag")
-
     # filtering out the conditions we are not interested in, to ensure here we
     # have a valid partition between the condition of the contrast.
-    #
+
     # XXX Hack for handling epochs selection via metadata
+    # This also makes a copy
     if contrast[0].startswith("event_name.isin"):
-        epochs_filt = epochs_filt[f"{contrast[0]} or {contrast[1]}"]
+        epochs_filt = epochs[f"{contrast[0]} or {contrast[1]}"]
     else:
-        epochs_filt = epochs_filt[contrast]
+        epochs_filt = epochs[contrast]
 
     # Filtering is costly, so do it last, after the selection of the channels
     # and epochs. We know that often the filter will be longer than the signal,
diff --git a/mne_bids_pipeline/steps/sensor/_06_make_cov.py b/mne_bids_pipeline/steps/sensor/_06_make_cov.py
index 075abe472..e3c8cdc9e 100644
--- a/mne_bids_pipeline/steps/sensor/_06_make_cov.py
+++ b/mne_bids_pipeline/steps/sensor/_06_make_cov.py
@@ -184,7 +184,7 @@ def retrieve_custom_cov(
         check=False,
     )
 
-    msg = "Retrieving noise covariance matrix from custom user-supplied " "function"
+    msg = "Retrieving noise covariance matrix from custom user-supplied function"
     logger.info(**gen_log_kwargs(message=msg))
     msg = f'Output: {out_files["cov"].basename}'
     logger.info(**gen_log_kwargs(message=msg))
diff --git a/mne_bids_pipeline/steps/source/_02_make_bem_solution.py b/mne_bids_pipeline/steps/source/_02_make_bem_solution.py
index 1320d6dc7..1f2947d01 100644
--- a/mne_bids_pipeline/steps/source/_02_make_bem_solution.py
+++ b/mne_bids_pipeline/steps/source/_02_make_bem_solution.py
@@ -99,7 +99,7 @@ def main(*, config) -> None:
         return
 
     if config.use_template_mri is not None:
-        msg = "Skipping, BEM solution computation not needed for " "MRI template …"
+        msg = "Skipping, BEM solution computation not needed for MRI template …"
         logger.info(**gen_log_kwargs(message=msg, emoji="skip"))
         if config.use_template_mri == "fsaverage":
             # Ensure we have the BEM
diff --git a/mne_bids_pipeline/tests/configs/config_ds003392.py b/mne_bids_pipeline/tests/configs/config_ds003392.py
index b8ee82d2e..108f4942f 100644
--- a/mne_bids_pipeline/tests/configs/config_ds003392.py
+++ b/mne_bids_pipeline/tests/configs/config_ds003392.py
@@ -37,6 +37,7 @@
 decoding_time_generalization = True
 decoding_time_generalization_decim = 4
 contrasts = [("incoherent", "coherent")]
+# decoding_csp = True
 
 # Noise estimation
 noise_cov = "emptyroom"