Blobby ends on unloaded filament causing load failure
I recently got my MMU2 successfully built, but I'm running into some pretty annoying issues trying to get it to actually print, as I'm frequently getting "MMU load failed" messages.
When I watch the filament loading into the extruder, I'm seeing that the end of the filament is blobby and uneven, which seems like a good enough explanation for why it wouldn't load correctly. Manually trimming the end to a proper taper solves the problem and allows the print to continue. However, the blobby ends are happening as a result of a previous unload, and this happens on a fairly regular basis. (I'd estimate one out of every ten times.)
Is there some setting I need to tweak to make sure that the end of the filament tapers off properly when it's unloaded from the extruder?
(For my filament, I'm using a couple spools of Hatchbox PLA, and I'm printing using the default settings in PrusaSlicer. The print temperature is 215, and the temperature of the cooling step during changes is 205.)