I’m connected to the 188.8.131.52 address on my own desktop with zero issues.
a) Can you ping either the US or Europe address?
b) Have you allowed the primeminer program/port 1337 in the windows firewall for the appropriate network zone?
c) Is your network behind a firewall that is more sophisticated than a standard home router?
That’s about as much as I can think of
edit: scratch a. I tried to ping it myself and it was failing. traceroute worked fine up until that final hop though. Xolo, did you really block pings?