Same issue for myself and my 2 friends..
FM23 will not allow more than one player to connect to the host on xbox live. This issue has been ongoing since fm22 as far as i`m aware it always breaks at some point.
Tried hosting a game on my PC through Gamepass for pc using the fm23 console edition of the game and it does exactly the same.
"HOST GAME STATUS"
Online Career - Friends Only - Password locked
Maximum leagues selected
Wired Connection
Open Nat (all players consoles)
All Using Xbox Series X consoles .(except when i tried to host on PC)
Game Updated to latest version on Hosts console, all other players consoles and Host PC (When attempting to host on PC Gamepass version)