If your Halo Infinite Multiplayer is not working or not loading on XBOX consoles then try first unplugging then re-plugging everything.
When your game data is on the external drive and it's a new gen game it may refuse to work so move some games you aren't playing to the external and move the game you are playing to the internal hopefully this helps.
ANOTHER FIX. For the "optimized for Xbox series s/x" games not launching, not opening, just move it from external to internal storage.
Reset your Xbox as a final thing to try to fix Halo Infinite not working or not loading issue.