Regarding a conversation with support (Case #03294892, BUG-000156931):
You must register the view with the [mobile] geodatabase for selections to work. Use the GP Register with Geodatabase tool to register the view.
That works as expected: I can register a view with the mobile geodatabase using the Register with Geodatabase GP tool.
However, I noticed that the equivalent action isn't available from the right-click menu of the DB view in the Catalog pane:
(The same applies to file geodatabases; there is no right-click menu option in the Catalog view to register a view with the file geodatabase. With that said, I don't know if registering is necessary for FGDB views or not.)
Whereas, with enterprise geodatabases, there is a right-click menu option in the Catalog pane for registering with the GDB:
ArcGIS Pro 2.6.8 Oracle 18c 10.7.1 EGDB
Idea:
Could functionality be added to the Catalog right-click menu for registering mobile GDB views with the geodatabase? (and possibly FGDB views too?)
That would be consistent with enterprise geodatabases and be more intuitive for users.
Food for thought:
This idea might also apply to tables that are created in the mobile GDB using a SQL client, instead of using ArcGIS Pro. Such tables wouldn't be registered with the mobile GDB either.