I’m on PC with the game installed via Steam. I use the Xbox game overlay’s LFG feature. When I message someone they say they invited me but I have no notifications within Windows or the Xbox overlay. When I search for that account there is no option within the game overlay or the Xbox app the join their fireteam. There is no way to search for this account within the Halo Infinite application.
How do I see their invite and/or how can I just join their fireteam? I don’t need this rando on my friend list without first speaking with them.
If someone invites me, regardless if I don’t see a blipped notification, I should be able to followup on that by just joining them. There is no way to do that. I don’t see a queue of notifications to followup on at all within the game interface.
I had this same issue playing with someone who was on PC while I played on Xbox. Didn’t receive my invite.
I’m not really sure if there is a good fix or not, but I think he just ended up joining my game via party chat menu.
It’s probably just poor UI for now though 
It doesn’t matter if they’re on PC or Xbox. If they’re not playing through steam, there is no way for me to join their fireteam, even if they invite me. There is no interface within the game or the Xbox Game Overlay to see invites and accept them.
For me there is a notification that pops up, but the invite ends up in the social menu where the friends list is. Assuming you have a setting in place that blocks the pop up try checking there although you may need to scroll down a bit.
Im having the same issue but for Horizon 5. Literally no way to accept an invite. You would figure there would be a simple solution right?
I mean, this video explains all that is missing for social features: https://www.youtube.com/watch?v=K1JID-Zgz6Y
In Forza Horizon 4 there was an in game menu to see your latest invite. I haven’t seen that in FH5 but I gave up on that a while back.
For realz, they need to have some playlists that combine the best of Reach and 3. Map vetos, after game partying, opt in proximity chat/all chat, lobby continuity (when balanced), etc.