channel navigation header tears away from side nav

[indirectlylit]

Observed behavior

at some browser sizes the header tears away from the side-nav:

Expected behavior

I would expect the side nav to continue scrolling up to the top when the header disappears

User-facing consequences

slightly broken-looking layout

Steps to reproduce

set browser width to ~750 px and view resources in library browser

Context

v0.15.0-beta1

[indirectlylit]

@marcellamaki FYI this behavior is improved in your PR #8637

[MisRob]

This was related to issues caused by certain layout of elements within one breakpoint. The layout seems to haven been updated recently and I can't find conditions to reproduce this particular issue anymore. I made some improvements in #8947 that were meant as a fix for this issue originally, but even without them things seems to work pretty well now to me, so closing.