I just noticed this new while testing the build that was released yesterday. I was simply experimenting with the new effect that has been added to Ripple and when I hit the undo button it strangely enough created a transition. According to the notes on how Ripple has been updated it’s not supposed to create transitions but it can when I sometimes hit undo.
I haven’t been able to experiment more to give a rundown on how this can be repeated exactly but since I am not going to be able to use Shotcut this weekend and there is a new build coming tomorrow I chose to get this thread started so that at least a clue can be provided that can help find whatever bug is going on in time for the new update that is right around the corner.
I think this is due to one of the bugs reported in this other thread. A couple of the bugs could have affected other use cases than what was reported due to the nature of the bug creating some inconsistencies in the data model backing the timeline.