This is something that’s making it difficult for me to use Ardour, but which I can’t reproduce in a way that’s useful in a bug report. I thought I’d post here to see if anyone sees the same thing, and if anyone has tips for working around the problem.
In my project I’ve used region layering heavily, to record e.g. 5 vocal takes and then comp the best bits. I’ve edited these takes using slice, mute, raise, and lower, and left all the regions in place.
The problems start when I remove a few bars from the song, and drag all the regions earlier to compensate. Dragging seems to mess up region ordering in various ways. Things that were not the top layer, become the top layer. One layer moves 16 beats earlier than another layer, when they were previously together. I reproduced this once (in safe mode) and made a video. I tried to reproduce again while opening a bug report – and it no longer happens.
I’m sure you know how frustrating that is 
Here’s the video. https://www.youtube.com/watch?v=lKqcg67GrXo
I’m interested if anyone else has seen similar things (this is Ardour 6.2 on Fedora 32); and if there’s a way to avoid these problems. (Using cut and paste instead of dragging does not avoid the problems – https://tracker.ardour.org/view.php?id=8348).
Thanks!
Sam