Visitor map: unknown cities, although geo-data for cities is available

Hi forum,

we use GeoLite2 Free Databases (https://dev.maxmind.com/geoip/geoip2/geolite2/) with Apache modul (Location Provider).

But at visitor map we see just unknown cities, although geo-data for cities is available and also displayed in list view.

See screenshots:

Is this a bug?

Matomo Version: 3.8.1

TIA & Regards
Robert

and here the working list view:

(just 1 img for new users / post allowed)

TIA Robert