I am experiencing the following issue with v.806 & v.807.
On the screencast I am adding a node and deleting it with Cmd+X. All this causes Glyphs to become unresponsive to the point that only restart of app will do.
If someone else is having this and need to work urgently on his master compatibility you can just downgrade to v.803 where this works without issue.
I have started this thread, since the other one seemed to have digressed a little. Also the issue persists in v807. You can check the original thread at the link below.
I have seen a similar case, and it turned out there were leftover stray points (single-point paths), which also explains the weird numbering of paths in compatibility view. There is a script called Delete Stray Points in my GitHub rep.
Cmd+X is cutting, not deleting. The new Cut behaviour leaves the end points of an open path selection intact. @GeorgSeifert: Perhaps that should not be the case if a whole open path is selected.