Ouch, that's a nasty one! Never noticed this!
I suppose it's just not logging snap key releases at all while an envelope is open.
Yes, exactly (because it's a different event loop for envelopes).
Interestingly enough, it seems that if you use a TAS snap keys to collect the envelope, you have to press any TAS snap key again to get unstuck, and vice-versa for snapping with the "snap field" button.
Yes, because pressed TAS snap keys are handled differently (especially regarding "pressed" state, due to that other (slightly related) bug in another recent thread.
I'll have to fix this...