Recently I enabled the dconf setting org/gnome/wayland/xwayland-allow-grabs. This fixed an issue where whenever I tried to use ctrl+alt+t (or any shortcut that used an alphanumeric) to open the terminal the desktop would then be searched for the letter "t"; however, enabling this setting also seems to have improved responsiveness system wide.
Likely not the culprit, but since both of these issues seem to involve mutter (as per kos's comment above) and sluggish inputs, I thought I would comment just in case it actually does help.
Cheers.