My printer seems to be slowly dying  

My printer seems to be slowly dying

A couple of months ago, I purchased and built the Mk4S to Core One upgrade kit (I also switched to the obxidian nozzle while I was doing the upgrade) .  At first, everything was working well (although I still don't think of it as a fast printer).  But after 5 or 6 prints I started noticing some failures.  At first I noticed the nozzle would hit the print once in a while, separating it from the bed. Then it would happen more often, and after a few days the head would start scratching the print on the second layer and if I didn't abort the print, it would eventually attach the head to the print and create a giant plastic blob.  I switched filaments (from prusament PETG to prusament PLA wood blend), and that seemed to work for a while.  Then I started seeing the same symptoms again.  at first the contact was minor and it would create some stringing or scratches on the part, but it would still complete the print.  And after a few more prints it would start aggressively scratching the print on the second layer and ruining the process.   At some point I tried re-running the self tests and calibration and that also failed the nozzle heater test, even though I was able to manually switch the temperature using the control menu without an issue.  After that happened I did a soft factory reset and that allowed me to complete the self test and even print a benchie without a problem.  But my next print started messing up on the second layer.  

Does anybody know where should I start troubleshooting next?

I have attached a couple of pictures and a video that show the second layer getting messed up before I cancel the print