I have a P2S with two AMS units. After printing a color, one spool does not cut filament cleanly and return to its spool to load the next color. It’s sort of a tug-o-war where the AMS tries several times to pull the filament back but cannot. Then it suddenly returns and loads the next color. Odd thing is it’s ONLY that spool. No other spool has this issue.
My P2S only has 88 hours on it. Not sure what might be going on (?).
Are you able to narrow it down further? In other words, can you nail it down to
That can greatly facilitate troubleshooting.
If it is the slot, it may be related to increased friction in the AMS unit. One of mine (still) has a bit of a gap in the AMS internal PTFE as it seems to have been cut badly at the factory.
But other things can be at play as well in this case such as debris in the gears, a lower spring tension or an internal hub defect.
If it is the filament, is it a bit more flexible by any chance?
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Thanks. I have a long running print going now so I’ll try your suggestion afterwards. The color was white in A1 with the issue so I added a 2nd white in A4 which had no issues like A1on a test print.
Next, probably tomorrow, I’ll move white spool in A1 to A4 and see what happens. I keep you posted. 
It’s the slot. Moving the filament from slot 1 to slot 3 fixed the issue. I have not tried a different spool in slot one yet.
That is also how I deal with the dodgy slot #4 of my “Friday-Afternoon”-AMS 
One of these days, I will get around to replacing the internal PTFE
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I now have found the issue happening on various slots on two AMS units. As the P2S is relativity new, I assumed the issue could not be the filament cutter at the hotend but apparently that was the problem.