Just have seen a post on Facebook where a user said that his/her teflon tube stuck out of the hotend and “collided” with the feeder wheels. Not sure if this might be an issue here? I guess it would happen on retraction. Just hearsay, was not able to relocate the facebook post for reference…
EDIT: Oh, stupid me, got this completely wrong in every way. It was not Facebook, but here in the forum, and not the feeder after all… ignore! I just leave the post here for the remote chance it still is somehow the same problem: Left filament feed tube getting caught between head and side of housing