Came here with the exact same problem that the AMS2 often jammed up when switching filaments. I first suspected it might have to do with the cutting of the filament because everytime i pulled the filament out, cut it manually and put it back in, it seemed to work (maybe because a smaller resistance). Saw this solution, compared it with my PTFE routing and behold… as soon as I nudged the grey PTFE tube in this position when it tried to re-feed, it suddenly worked. So my quick fix is: i put the grey PTFE next to the white like this and secured it with a zip tie in that position (not completely tight so there is still some freedom). Result: it works so far! A model with several color changes finally printed without issues. I hope that a simple zip tie now permanently fixes the problem.
I’m 400 hours in on my X2D and it no longer feeds filament past the buffer. It stops at the buffer immediately and reports a problem with the PTFE tubes being in the wrong order, this is entirely not true. This machine has been running great other than this new feeding issue.