Something is not right. That number should be basically the circumference of the chuck or pulley driving it. Closer to 120, not 4. For the roller, it is typically 40 or 80.
I think you need to redo your rotary setup to see if you get different results. You should not have to be messing with GRBL parameters. $131 is Yaxis max travel, and has no bearing on a rotary because it can make lots of revolutions. [I hope you made a backup of the parameters before changing them.]
Here is a Posting I did a while back. The value for the setting on my chuck is 130mm, and the roller is 40.
Chuck = xTool RA2
Roller = Atezr KR
And another set of instructions that is very good.