This has been an odd one to figure out, and I'm hoping this makes sense. It requires multiple very specific components to make it happen. I wasn't sure which sub-forum would be the best for reporting this, and went for Multiplicity since it seems to be the main contributor here.
The variables in place:
- OS: Windows 10 Pro 22H2
- Start11 installed: v1.47
- Start11 configured to place taskbar at the top of the window instead of the bottom
- Multiplicity installed, as Primary, version 3.6 build 00105.kvmpro
- Multiplicity is connected to a second computer either via KVM or Seamless (both can trigger this)
- Firefox browser installed, version 122.0
With these in place, after opening the Firebox browser and spending some time doing regular work computering, at some point in the dozen or so minutes that follow, the taskbar becomes un-clickable. Meaning, no icons or programs shown on the taskbar respond to clicks, making it impossible to switch apps using the taskbar (alt-tab, manual window clicking, and other methods still work).
The only way I've found to make the Taskbar clickable again is to completely exit (not minimize or resize) the Firefox application. Upon doing so, the taskbar is clickable again as normal.
I strongly suspect there are other variables contributing here, but these just happen to be the ones relevant to my current repeated observations.