@Gettysburgx
It is TCP. You might need an "allow-rule" for triplea.exe on different ports.
I have usually opened port 80,443,587,3300,3304
(587 is needed for PbEM only).
Again which specific port is needed might be shown in your firewall log.
For a brief test whether your issue is firewall related you could take the "risk" for a short moment and test joining with the firewall being deactivated. Just in case you don't want to dig too deep into it.




1888A Steam & Steel
219
d8
2.7
PU, Tech, Diplomacy
8 faction FFA, 5 TT Random allocation, Tech Tree (like Age of Tribes), AI will go to war and get impending winner alliance, Custom Production tabs, Upkeep, Simulates winter
Over the Top
451
d6
1.9
PU
11 Player, PvP only, Railways (Canals to simulate railways like Civil War), Tech Trees (like Age of Tribes), 3 move phase (usually 2)