Thank you! The first suggestion worked. The issue was from my side. I was using the app as the article said, but on the pictures it shows that i should use 1.1.1.1
And so i did! It didn't work. After some time I tried to use the WARP feature of the same app and it started working as it should.
Now me and my friend can play both in the server.
I'm very grateful! Happy holidaysl
Best Wishes,
Martin!