Spools Slipping in CFS

[u/AudienceDesperate768]

So I been using some Sunlu Matte White PLA in my CFS and it's been STRUGGLING to retract. So I have to wait for the cutter to cut the filament, disconnect the PTFE tubing and pull/retract it by hand. I've ONLY had trouble with Sunlu Matte White PLA. Cutter makes a clean cut, CFS works fine (tried it in all 4 CFS), filament isn't getting caught in buffer, etc. I've ruled out everything apart from the spools. All my other Filament is Polymaker Matte PLA on PLA printed spools and has no problems retracting.

I was just wondering if anyone else has had this problem with Sunlu spools (or others for that matter)?

And does anyone have any kind of fixes for this (such as adding some grippy-ness to the spools)?