Ip Lookup service - Geolocation problems with Geoip2

Your software
My Mautic version is:
My PHP version is: 7.2.26

I’m facing several problems with ip geolocation.

The first one is that I don’t get a feedback if the IP lookup service authentication credentials are ok or not.
I created an account with Maxmind geoip2 precision and inserted the credentials like “user:apikey” or “apikey” but I don’t know if they are accepted by the system.
The funny thing is that if I don’t write any api key I still get geolocation information in the contacts screen!
So I think that the connection is not working…so where Mautic is getting location data from?
There’s any cache system that caches Ip datas?