I have just been testing the edit playlist feature on android v 80.21.3 os v 85.0.64200.
I started with a playlist playing in the queue and then as I was listening to each track I had the edit playlist function open and started deleting tracks from the playlist that I no longer wanted (NOT from the queue itself).
After about 10 minutes of editing I was astonished as some of the entries I had deleted reappeared in the playlist right in front of my eyes without me touching anything.
I then reviewed the playlist and found some of the tracks I deleted earlier in the session had correctly been removed whilst others had returned BUT worse still was that tracks I definitely didn't delete have been removed from the playlist. ( I noticed this as it was a track I hadn't even got to in the playlist).
So not only had I wasted 10 minutes of edits I have ended up with random tracks missing. I now have to restore the playlist and start again.
WHAT IS GOING ON?
This would have been easy to miss if I hadn't been focused on what I was doing. How many people would miss the odd track going astray?