I think it has to do with Wow file rather than Server i think. Maybe Add wow server app on Firewall. Then try having your local IP as your realm address etc. After everything not working restart your computer then change everything back to default. try again if it doesn’t try deleting your wow folders cache.
I’m having the exact same issue. I am using Debian 10 (TrinityCore rev. f6094712de2b 2021-05-08) for my server and on Windows 10 I am using WoW 9.0.5 38134 client with the 9.0.5 Custom Server Connection Launcher and it just sits on “Logging in to server game”.
Under bnetserver.conf and worldserver.conf do you have these settings below? In addition, when you type winver in your Windows run command what version do you have? I am using version 20H2 .