Keyboard Jogging Problems!!!.

 I've seen some other people posting similar issues, did these problems start with the switch to GTK3 or might it be closer connected to the switch to Preempt RT or a later Debian version?

I'm not really competent to determine exactly what's going on, but I did look through old GH issues - and there are a number of similar reports over the years.  They go back to 2.7.

However, there may be two (or more) underlying problems which present the same - more or less - undesired behavior.

I get the sense that one of the scenarios involves switching tabs or otherwise changing window focus during a continuous jog.  At the very least, something other than just pressing/releasing a keyboard key is happening.

The other scenario is what the OP reports - no change in window focus, no pop-ups, nothing but a continuous jog even though the key is released.

The two scenarios may not have anything to do with each other beyond the end result.

My suggestion for the OP would be to turn off keyboard auto-repeat in Debian settings and see if the problem continues.  If the problem goes away this may point to a Debian change rather than an LCNC change.