We figured it out, but we don't know how to fix it. When we remove the mods in the net logs we get
[2024-08-25 10:14:28] [Connecting, 4, 0] [A:1:0:0] CM Directory list says 97% of connections should be websockets, we rolled 5 - using WebSockets as default.
But when we add them we get
[2024-08-24 21:10:31] [Connecting, 4, 0] [A:1:0:0] CM Directory list says 97% of connections should be websockets, we rolled 99 - using UDP as default.
So basically its the game decided whether to use TCP or UDP as the default protocol. When it uses UDP it won't advertise out, but when it uses TCP, it works fine. We also verified this with other servers being used, they are only connecting via Websocket/TCP and not UDP.
I submitted a ticket with Bohemia, hoping they respond.