Waveform glitch?

[A-Winters]

I've always loved Subtitle Edit and the latest update is a huge leap and it's even better, so well done!

Waveform is very useful, but it seems to have a glitch when I try to drag lines to expand or shorten dialogue. It 0deletes the part I'm trying to move and replaces it with a duplicate of the previous line.
I try the "undo" option and it's like the deleted line never existed.
Sometimes the lines get displaced, but more often I lose them altogether.

It seems that Waveform really dislikes anything on it being mouse-dragged.

This has been a problem since I discovered Waveform months ago, but I've been forgetting to mention it.