Agreed. This year I have experienced only a couple crashes and hitting accidentally the Caps Lock key while doing edits at the same time has something to do with it. No real problems with tools. GMIC has had more stability issues.
Ubuntu repo Gimp can be out-of-date, especially if you have sticked with LTS-Ubuntu.
I have installed Gimp 2.9.5 from the ppa below and the maintainer has got also an another ppa for up-to-date 2.8.x
This can also give a nice starting point in Gimp, works well.