This is what I see when I open the production tab in a city that only has a harbour, therefore only being able to produce naval units.
You can see that it is showing Air units instead of Naval units, as the Air icon is selected within the 5 above the units per se, however, it should be opening like this
it is a minor problem but I think it should be fixed, same applies to the rest of units, if it only has 1 specific building to produce units, then the scroll should directly go down to show the start of that group, not half of it or the end of it, just like shown with the naval units
could it be a resolution thing? i don't think so, zoom doesn't seem to change anything