I’m afraid I can’t address “fixing” your issues but can point you to the fairly lengthy “$79 laser engraver on Amazon… any good?” thread – that you participated in – and might help you remember some details about this little machine.
IIRC the Grbl firmware we loaded onto that machine was actually for a similar but different JL3 machine… that I think was a larger version using the same controller. Maybe that’s where the Y -360 coordinate can from?
As I shared in the post above, the JL1 machine runs quite nicely IMO in “current position” or “user/job” coordinates… without the need to “home” it. I find the machine is so small and it’s easy enough to simply manually place the laser where you want the job origin to be and then power it up. I’ve still got this little machine and found it really handy for small jobs like ceramic and/or slate tiles…
– David