Recommended · for beginners
Fixing a Filament Flow Problem on CR-10 mini, CR-10 or Creality Ender 3
Why people recommend it
CHEP traces under-extrusion on Creality printers to the PTFE tube slipping in the hotend coupler and shows the fix; recommended for Ender 3 flow problems.
Watch for: gap between the PTFE tube and the nozzle
In their words
Fixing a Filament Flow Problem on CR-10 mini, CR-10 or Ender 3 by CHEP
Tinkerman255 on 3dprinting.stackexchange.com, Mar 2019. CC BY-SA.
I haven't experienced any such problem myself, even after applying some fairly serious abuse to that part of my Ender 3, but this video from CHEP claims it was the source of his problems and explains the issue well.
R.. GitHub STOP HELPING ICE on 3dprinting.stackexchange.com, Sept 2019. CC BY-SA.