I have attached an example I came across while modeling today. Sometimes I get failures on basic geometry that I've inspected and not sure why?

I proceeded to separate and manually build so that I could keep working but I'm curious if there is something I'm missing as to why these two solids won't join properly?
I wonder if there is a distance from 0,0,0 that can be at issue or units maybe? I have default units at inches and modeling in inches as I'm in the U.S.

Thanks!

Jason

P.S. I made the cylinder and back of plate to have tangency and no floating numbers so they mathematically should be coincident.