After adding our 365 tenants and performing successful discovery, we attempted to match one user by DisplayName as a test and it failed.
We also tried doing a CSV mapping by UPN which also failed. There doesn't appear to be any reason listed and the diagnostics only shows some simple data like the Org, Project and task ID.
I've gone over our consents and they appear to be in order. I'm not quite sure what else to check.
Was not able to find a topic in the forum that helped.