Filament stuck at top of extruder
I have been using my Prusa for almost a year now, and I haven't run into this problem.
Something is blocking the filament from entering the hotbed pulley, my guess is that there is a piece of filament stuck in there. But I can't get it out. There is nothing in the manual about dealing with this particular issue (that I can find) as it always seems to deal with stuck filament on the nozzle side. I'd be very grateful for ideas on how to fix this.
Take a look at:
https://help.prusa3d.com/en/article/i3-printers-regular-maintenance_2072
Scroll down to "Extruder driver gear"
If the area is clean the most likely block point is a worn or damaged PTFE tube, if the bondtech alignment is even marginally off it will wear unevenly in time and deform at the top.
If the blockage is above that, the filament sensor may have come loose somehow.
Cheerio,