I can’t be entirely certain which fixed it, but I had some environment variables that disabling seemed to resolve my issue(s)*. The ones I’ve disabled are QT_X11_NO_MITSHM=1, QT_QPA_PLATFORM=wayland-egl, NVD_BACKEND=direct
These were originally added to fix other issues/enable other features, and don’t seem to be necessary anymore. On the contrary, it appears one or more of these were outright causing problems.
*Other annoyances are also magically gone (clipboard seems to actually work more than half the time now, drag/drop into discord works, drag/drop into tk isn’t a coin toss, etc)… so… yeah… I earned my dunce cap.