I really think this is a bug, but here goes:
I have a project with a gazillion maps
I want (2) in this new layout I just fired up
So I go to Map Frame and.....after scrolling up and down for 4,002,132 years, I eventually find it
Note how the sort order in the Map Frame drop down.....is not sorted in any way I can determine, nor can I control it.
Same if I do this:
I realize I can just drag the map over into the layout from the cat pane, but that gives me a map zoomed to the extent of the basemap layer (world), which I was sadly told is not a bug