Problem: ArcMap 10.8.1 open with a blank map file. Insert another data frame in addition to the default one. Now you have two different data frames. Add different vector layers into the two different data frames. Try to do Select by Location.
I see possible Target Layers and Source Layers only from one of the two Data Frames, irrespective of which one is active. Even if I switch between activating different Data Frames, the Layers showing in the Select by Location dialog box show only layers in one of the Data Frames (sometimes not the active one).
Expected behavior: The possible Layers showing in the Select by Location dialog box should be from the active data frame.
Only if I activate the desired data frame and then save the map file, then restart ArcMap and open that map file, will I see the expected Layers from the active Data Frame when I go to the Search by Location dialog box.
What might be going wrong?