They might have tagged you before you went on the VPN and then it doesnt update your IP.
They might even know your going through a VPN and discard the VPN ip address.
Maybe, just guessing. It does sound funny.

writen by Stephen N
But actually when I am with VPN on splitbee changes my location to the one of the VPN. So maybe it’s an issue with your VPN?

writen by Tiago Ferreira
Either there’s not all traffic routed through the VPN or they already could identify you (fingerprinting) before you used the VPN

writen by Benedikt
NordVPN is one of the best. I can bypass pretty much anything with it and it changes my ip everytime. But for some reason, simple analytics still can track m

writen by Dobroslav Radosavljevič
Maybe try with that and see if it changes the results. If they (simple analytics) use some kind of cross reference with other sites using it that might be a very sophisticated reason as well

writen by Benedikt
From the documentation https://docs.simpleanalytics.com/what-we-collect
> In contrast with most services that collect countries based on IP address, we collect them based on the visitors time zone.

writen by Sanat Hegde