AMS fail to pullback

I’ve only been using my AMS a few weeks and had this happen twice now when the spool near is empty. The spool with just spin and it won’t pull the filament out cause it’s just loose and not tied to the filament. Is it normal for this to happen? Not sure why it decided to retract except maybe to get ready for a filament change. I’m using up a couple Elegoo black pla I have left over. Should it be taped down to the spool so it stays tight?

I usually just use same tape to hold the filament on the spool.

The real bother is having to watch repeatedly for when to release the filament from the tape again. It is a pain to get shreds out of the extruder …