[Trinus] Printer started getting a problem, what could be wrong?

[veclock]

Hi again, thanks for your answer!

What exactly is the PTFE lining? I disassembled the extruder. Looks like the tube leading town to the hotend is a bit bent. But that shouldn't create too much resistance for the filament to flow down?
Also, I can't change the nozzle, not sure why. As you can see in the two images to the right, there are filament leaking (?) between the parts, perhaps that's why the nozzle is stuck. I wonder if it's clogged inside. I can push the needle through without a problem. And it prints fine, with enough filament coming through. It's just that it skips steps all the time.

Image: https://i.imgur.com/JsWgAYL.png

Update: managed to remove the nozzle after heating it up. I looked inside the pipe and the nozzle. No clog. It was dirty on the outside.