I just saw this. What printer is that (looks like a Creality layer cooling fan)?
If it is a Creality printer and you still have the stock plastic extruder - have you checked the extruder arm for cracks? They usually appear on the underside of the arm around the pivot hole.
It looks like the problem happens suddenly like it's fine and then it's a mess. If that's true then it appears to be a mechanical issue rather than the filament.
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