Only one debug console can be used at a time

[tmk]

You can't open multiple 'hid_listen' sessions at same time. If you connects keyboard/converters with PJRC HID debug console on a host you can get messages only from one of them and not from others.

WORKAROUND:
Disconnect other devices with console except for one you want to debug.

SOLUTION:
We will be able to make altenative of 'hid_listen' or improve it so that it can select a device out of connected keyboard/controllers to debug.
https://www.pjrc.com/teensy/hid_listen.html