Restarting helps, but again for a couple of minutes.
Affected device: touchbar
Device information:
Type of Mac: MBP 2020 Intel 13"
macOS version: 11.4
BetterTouchTool version: 3.562/3.564 alpha (tried both versions)
UPD
If I click "Show macos control strip" in settings, a "You have not configured actions in BetterTouchTool" message appears for a fraction of a second. Not sure if helpful but think this might help.
Ok, my bad, found the problem. I use shell scripts to run local php files. After OS update local web server stopped working returning not the script execution result but the script itself.
But thanks for the tip, it gave me a direction to investigate