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 .
bnetserver.conf
LoginREST.Port = 8081
LoginREST.ExternalAddress=127.0.0.1
LoginREST.LocalAddress=127.0.0.1
LoginREST.TicketDuration=3600
worldserver.conf
WorldServerPort = 8085
InstanceServerPort = 8086
BindIP = "0.0.0.0"