Either youre hobbed bolt isn’t lining up with the throat or the throat is clogged. there is a ptfe liner in the throat so you shouldn’t see excessive backups like this just because the fan is breaking down. unless you keep your house 90 degrees. you need to pull the nozzle and throat and make sure they are clear. your fan also needs to be addressed for sure, but your extruder shouldn’t look like the picture unless you didn’t get the filament lined up properly, if it was filament backing up in the hot throat then you’d see some oozing somewhere around the throat. it could be something as simple as a tiny little nic in the ptfe liner.