I don't know if this is a problem but I'll tell you anyway.
I installed a program called Plex that automatically turns on IPv6 on your PC (Network & Sharing Center > Change Adapter Settings > (pick a connection) > Properties > IPv6).
Afterwards if I run pager it can't connect to any game and can't refresh the game list etc.
All because the IPv6 checkbox is ticked.

Would never have been able to fix it if someone else didn't know already and told me the issue. I just unticked the IPv6 checkbox and it works again.

Maybe BYOND pager should warn users with IPv6 ticked to untick it so they have a clue to go on.
I've had IPv6 enabled for quite some time without issue. I do know that BYOND requires IPv4 to run, but having IPv6 enabled shouldn't prevent it from using that unless something else in your setup is preventing you from also obtaining an IPv4 address.