We are experiencing this as well. I contacted support and they informed me that it is a known bug with Pro 2.0 and Desktop 10.5.1: BUG-000106595 - ArcGIS Pro 2.0 and 10.5.1 Desktop require explicit object level select privileges for users to view SQL Server geodatabase data in the Catalog tree. There is a patch for 10.5.1 Link released last week but no word on a fix for Pro at the moment.
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