We have been at ArcSDE 10.3.1/Oracle 12c for almost 2 years and have a lot of spatial views. Recently we found a few spatial views in existing ArcMap files do not match ArcCatalog (verified in both ArcGIS Desktop 10.3.1 and 10.5.1) in feature count, and we have to drag the spatial views from ArcCatalog into ArcMap to validate the count. Anybody knows why? This behavior really looks like a bug to me.