Do you have a single MGN rail on X or two? It’s easy to end up with twist on dual X rails that can be a bugger to try to straighten out.

Also, are you doing a good heat soak before printing, and do your probe results change at all before and after heat soaks?

If you’ve got a beacon on there, it seems like it would be well worth cranking the probe points way up.

If it’s simply bed adhesion, definitely give the dish soap method a try if you haven’t already.