Consistent Clogging on one side of the hotend assembly in A20M

[Oddity]

Hi,

I have had my A20M for over a month, and have never once successfully printed a multicolor part. I level the bed, clear the nozzles, ensure that each side can extruder correctly, and always after a few layers, Extruder B starts to click. When I remove the Teflon tubes from the hotend assembly, I find that the filament from Extruder A is fine, while the filament from Extruder B has balled up on the end. I have attached a picture showing this. In the picture, the black filament on the left came from Extruder A, while the green filament on the right came from Extruder B.

I can not figure out what causes that side to ball up like this, but it prevents me from using that side of the hotend assembly at all. Please advise on how to fix this.

Thank you,
Oddity

[William]

Hi,you can check that the hot end part is partially blocked, heat the nozzle temperature to 200 and then manually push the consumables. If the blockage occurs, use a tool to clear it.