I changed to an all metal heat break on my Ender 3 Max and the first print went great but now I am having issues. It does not start printing after I confirm the print, it just sits there. It may start after several attempts, stop print start print, power down then back up. The two things I have noticed is that the XYZ positions either blink or show ???. The other thing is that if the nozzle temperature is set to 200 it goes between 195 and 205, never stopping at 200. This continues during the print.
Check the wiring on your hot end. I’m going to guess a loose or broken wire
Thanks, I will take a look.