End-user with Admin status cannot access contacts in database.

Thank you all for your help.

We ended up removing all privileges from the account, and re-adding them, which fixed the issue.

I'm told there was a major update, could that have caused this?  We have a number of other users without issue, with the same level of access.

Interesting approach.  What do you mean by removing their privileges?  Did you change them to a regular user and then switch them back to an Admin or are you talking about teams and roles?

Yes, the administrator removed the "teams", applied the changes, then re-added them.