I created a listing and used the map (Open Maps) to locate the listing which automatically created the Location, Region and related slugs etc.
I noticed later that the city name had been created with the same name as the region. I realise this is an issue with the data provided by Open Maps.
Anyhow, I managed to correct the city name through the Settings > Locations tab and it all looked correct.
However, that location with the corrected name and slug is now showing 0 listings under the Settings > Locations tab.
The listing itself is still there but is associated with the original (incorrect) city name and slug and I had to edit the individual listing to associate it again with the same location ID (but now with the corrected location name).
Shouldn’t changing the name or spelling of a particular location ID automatically change the city name/slug of the listings associated with that location ID too? Otherwise it might leave a lot of manual editing to do on a large directory.