Background:
I have a top-level assy. w/ 15 sub-assy. Everything functions as designed mechanically.  I bring in one more sub-assy, to top level.  I create mates on front plane, right plane looks good then make final coincident mate between two sub-assy and I get over define mate. This is not just one warning but in five of the sub-aasy, so a total of a dozen warning. The warnings could be coincident, parallel, concentric, angle mates.

Need /Tried:
I need this last coincident mate between the two sub-assy so they can move (rotate) together.  I have checked all previous mates in sub-assy and top level and all looks well. I have tried an Advanced Mate, (Symmetric) w/ same results as above.

At this point I’m not sure what else to try or to check, any ideas?

Happy Thanksgiving