Unfortunately, I still haven't received a clear answer from anyone. No one is blocking anyone else, yet there is no connection.

By the way, tech support wrote to me saying that "some IP addresses used within Ukraine are treated by certain foreign servers as addresses registered in occupied territory, so they block them." Sorry if this sounds a bit blunt—I wanted to avoid politics—but that is the response I got from Kyivstar.

Hi everyone, did anyone manage to solve the problem? I ran into the same issue with the same provider; Kyivstar suggested I buy a static IP from them, but that didn't help at all...