PLA Suddenly Jamming Mid-Print

[Ryuluce]

Is the heatbreak/throat PTFE lined or an all-metal one?

PTFE lined. I actually fairly recently replaced the PTFE lining with a spare that came with the printer.

BUT, this is the more important part: I actually got a print to finish!
The print is soaking at the time of writing in limonene to remove the HIPS.

Here's what I did that made it (I think) work: I turned off the direct filament cooling.
So far, my theory is that the cooling apparatus was cooling the nozzle of the PLA extruder making the gear grind down the filament.
I plan to upload photos of the print when the support material is done. I haven't gotten a second print done yet to make sure it was not a fluke yet because I was having some trouble getting the PLA to stick to the raft of this other test print. I don't have the time to mess with it at the time of writing, but I'll likely give it another shot after some tweaking tomorrow.