Interesting. I reported something similar, in the MIDI Editor, as a bug.
https://forum.cockos.com/showthread.php?t=193808
Seems to be related, including the part about SWS: Undo Zoom not getting you back to exactly where you were.
Can happen when opening window in unopened docker/closing last window tab in docker. Tried FX Chain, Mixer, Media Explorer, Routing Matrix.