I have a Bambulab P1S with an AMS. Every now and then I have issues where the filament gets jammed during printing. Of course, this can also be caused by poorly wound filament. However, I’ve noticed that there is a strong pull on the filament spool when the filament is being fed in. The two rubber rollers do not rotate during this process. Shouldn’t they also rotate when the filament is being pulled in? When the filament is retracted, the rubber rollers do rotate.
I have a tendancy to unwind my spools a little , more so as they become empty, this helps with the initial load ,it also helps prevent the spool being pulled over to one side ,when filaments are loading from the side , mine being pulled left to right which instantly appears to lock it up, (resistance) which i believe is the intention, to prevent further issues . (ams 2 )
simply lifting the spool of the rollers and replacing it , appears to reset them and you can check by giving them a quick rotation
Thanks Neiljt.
But I wonder, shouldn’t the rubber roll not be driven when the filament is pulled in?
The front rollers should be free wheeling when the filament is being pulled in but there are not driven at that point.
Are those BL spools you are using?
I finally found the issue. The rubber on the roll was a little bit slipped on the ball bearing. So the roll was braked a little bit 
How many hours are on it? The PTFE tubes in the AMS (and else ware do wear out. They wear a grove in the side of the tube. Eventually it wears all the way through the tube sidewall. This grabs the filament. The first time it happened to my printer was around 4000 hours. It depends on what filament is used.