Recently I have trouble assigning to a server; if I sign up for Amsterdam - when opening the browser, it tells me , my site is Teheran - that is very strange. Also there are new cities on the list, which I never saw before

There is a Teheran restaurant in Amsterdam, could they be running a VPN server ??

Change the Google search location to your liking. Google doesn't geo–locate based on the registered location exactly — they might have picked up the location from other/earlier VPN users of that node that then set their location to that value.

Basically if you open https://iplocation.io/ it will give you some more data about how the various services see your current node "from the outside".