im having trouble printing makergeek en7000. it strips the filament if i remove it put it back in it prints again.

i tried in 3 different hotends a e3d clone all metal, and one with ptfe liner and a stainless steel DURAPLAT3-D coated. the ptfe lined one will print for 20 to 30 min the others just a few.

things i tried
temp 240-270
speed 15 to 40mms
tightening pinch roller
turned off retract

i can print others materials fine with these hotends.

any tips to try?
thanks

Have you seasoned the hotend? Apparently, all-metal hotends can greatly benefit from a seasoning run here and again.