This is an annoying little issue I have had for the last few months both on X and Wayland. On my touchpad I lose the two finger tap context menu for all windows except for those with hative decoration. So I have it for Gedit and Calculator, but not for let's say Synaptic and and Slack. I can still get the menu with the right mouse button, but I am so used to the two finger tap on the touchpad it's hard not having it there. I know I had it until the beginning of this year and right after I upgraded to 21.04, but now it's gone again. I sometimes have it for a few minutes after reboot but then it stops working again.
I'm on a Thinkpad Carbon X1 7th with stock Ubuntu 21.04 upgraded from 20.10. Any idea why this happens and how I could potentially troubleshoot it? I have tried disabling all extensions but I still have the problem. I have tried to create a fresh user account, same issue.