Bed leveling woes

I’m in the ‘can’t calibrate my print bed’ category. It worked for the first few prints; and then I started gouging boards. I followed this video to try and solve the problem here:

What I can tell is my z-offset isn’t correct; however it’s not repeatable. For instance, if I change M206 Z (normally at 0, the video suggests a higher value, but his value didn’t work for me) to -0.5… I ended up with it being off as it transitioned the board in the X axis. So, I adjusted to -1.0 and that caused it to gouge almost immediately (previously was the ‘high’ spot.

If you’re interested in seeing what your bed level looks likes visually, he shows you how to use Excel to chart it. Mine is off by 3 units roughly from front to back.

Any ideas? Yes, I’ve sent an email to support. I’m FW 1.10.1 for reference and I installed it before I used it at all. I’ve gouged through all my boards at this point. It’ll be a few weeks I imagine till I get more from snapmaker and Imakr’s prices are ridiculous.