Missed that somehow. "Installed a new teflon guide tube" thought this the tube leading to the extruder!

Have you checked the Stepper current, is the Spring tension weak.
Do not know if this applies, thou on my printer when I was using a new slicer and somehow it managed to change the configuration, in order to correct the problem.
I had to restore firmware settings using M502 "reverts to the 'factory defaults" and M500 to save the 'factory defaults'.