Ah, the infamous tape. The Bambu filaments are taped down at that end to the core of the spool. Depending on phase of the moon or whatever, the tape may release properly, may stick and not let go at all, causing an error, may let go the spool but stick to the filament, jamming up the AMS, or may release prematurely making the AMS not be able to retract it if it needs to. There may be some other things it could do, really… quite unpredictable, that wily tape.
Other threads (there are more):
H2D AMS 2 Pro gets wedged if end of filament fails to detach from spool,
Tape at the end of spool,
P2S + AMS Pro 2 Filament feed when end of spool
So yea my “auto” refills haven’t been very auto because I babysit the spool and snip the filament just before the tape as it is about to run out. Then the auto-switchover works great! 
Personally I’m not really “sold” on the anti-tape devices I’ve seen out there… a complication that most of the time just increases drag, seems like, and adds point of failure. But yea would be nice to put a reliable “auto” into that “auto refill” feature.
-Max