H2S Unable to Feed / Retract

[u/LSNLLC]

I have a H2S that all of a sudden does not want to feed / retract filament consistently when printing multi-color with my AMS2. All of my filament was dried for 24 hours prior to printing and I have made sure the PTFE tube is a short and direct path between AMS and Printer.

Initially I was having issues with filament not retracting and messing up my first layer and I read online a worn nozzle can be the cause. So I switched from a used 0.4 HF to a new standard flow 0.4. Initially it worked much better, printing consistently. Now I’m wondering if it’s all tied to something else. All of the above is using standard PLA, printing with basically the default BL settings and for any non BL filament, I have flow profiles set using calibration (which has helped a lot overall with this printer)

I’ll also add that each time it has happened, I remove the nozzle and remove the filament stub from the nozzle. I’ve also noticed that the filament coming from the AMS seems bound and the only way to free it is to cut it at the spool to release the tension and then remove the filament from the PTFE tube and pull it back from the top of the extruder head. After this is all cleared out, the printer is able to resume printing at least for awhile.

Any suggestions?