I’m changing the PTFE in my heatbreak, I didn’t realize these seem to be consumables. It started causing blockage.

A guy sent me a piece of PTFE from his Prusa MK3S+ that I could try as i was having trouble finding any PTFE quickly.

I realized I couldn’t just cut a piece and put it in, that caused a lot of filament leakage and underextrusion. The end of the PTFE toward the nozzle was a bit jagged and I believe that’s where the leakage happened. Now I’m wondering how the heatbreak and nozzle normally interface inside the heatblock, should they be touching? Should the PTFE protrude a bit from the heatbreak so there’s a bit of pressure against the nozzle when I screw it in?