Look for the cause
Enter $# in the console – this will print the current coordinate offset values for G54-G59 work coordinates, G28/G30 pre-defined positions, G92 coordinate offset etc.
Fix the problem
Enter $RST=# into the console – This erases and zeros all G54-G59 work coordinate offsets and G28/30 positions stored in EEPROM.
* Please let me know in the comments the results of $# and if $RST=# fixed the problem.
I tried this fix. It worked once and then it went back to plunging into the work again. I retyped it and it didn’t work the second time. It still plunged into the work. The only thing I didn’t do was put a tool in so I didn’t break one this time.