There are many reasons that you could be connecting to a host outside of your Geo-Filter. They include:
Many of these problems are easy to fix. Follow the steps below to fix this issue. Please make sure that you are running the latest version.
Please check that the following options are set correctly:
You have enabled the Geo-Filter.
The tick box for "Enabled" under the selected device should be ticked.
You have strict mode enabled
Having strict mode enabled will mean that you can only connect to hosts within your Geo-Filter, but it will also mean that it will take longer to find games. If you have it disabled, you can connect to dedicated servers that are outside of your Geo-Filter.
It is not Ping Assist
If the above hasn't solved your issue, then it could be the Anti-cheat Feature.
Turn off your console for two minutes (until the dormant hosts disappear) then load the game back up. Try searching for a game without changing the Geo-Filter distance.
If you carry on connecting to servers that are outside of your Geo-Filter, carry on through these steps.
Restart the NETDUMA.
Settings > Miscellaneous > Reboot Router
Try searching for a game. If it is still connecting you to hosts that are outside the GeoFilter, please make a post on the support forums.