Nozzle always "randomly" moves to 0 during print, then resumes
I see two problems in your video:


It looks like the first layer is built too much upwards. (The level calibration should be so that a Z-height of 0 can barely fit a sheet of paper under the nozzle. )
Your printer is not extruding at all. As you said, the extrusion has some problems. Extrusion problems will cause adhesion problems too.