ArcPro removing the same feature layers

[JasonKesling]

I am trying to add multiple of the same layers (buildings). When I add one, and then add another, ArcPro automatically removes the first one.  I need to have about 3 or 4 buildings on my map, but for some reason, ArcPro is only allowing one. It does this with other feature layers as well. 

[Robert_LeClair]

By chance, do you have a Definition Query on the feature layer in the Map View>