Property Line Dispute (MI)

I recently bought a house with 50 acres. When I bought the house, I walked the property to find the corner markers.
Recently, I was introduced to Onx and Regrid, which shows my property line with the corner markers about 50’ off. Talking with my other neighbors, the neighbor that I have a question about the property line with, evidently he put the stakes in himself. Since having these stakes in, he has put in an access road (prior to me purchasing the house) and cut down a number of trees (some while I own the house). Given I want to figure this out, I contacted a surveyor to figure out this mess, but I wanted to ask:

1. ⁠Has anyone dealt with this type of situation before?
2. ⁠This neighbor is mean, the only time I met him on the road he told me to F-Off when I introduced myself to him
3. ⁠What advice would be given for my next steps if the survey does show his markers are wrong. I did the math, its about 1 acre that he assumes he owns, which does not line up with any County GIS data or any apps. His road and the area he has cleared is on my property.
   I understand these apps can be inaccurate, hence getting an official survey done is my first step.

Location: Michigan

Thanks in advance!

Author: RuralNorthernHick