Alright I think I may have identified the issue.
Domino 500.
The pin that holds the fence is sloppy the whole way across the machine. As a result, it doesn't consistently land at 90 degrees. It looks like 90, but I have to hold a square to it and clamp the fence in order to get it to perfect 90. It naturally goes to about 91 degrees if I don't back it up. I re-ran the test after clamping the fence with a square and sure enough, everything came out perfect.
Anyone else having to mess with this on theirs?
Attachment 483069