A Game Invite Was Received, but you can't accept it

Starting yesterday, I started to receive the following message when trying to enter the Eliminator (or other online mode) on PC:
“A Game Invite Was Received, but you can’t accept it at the moment because your profile doesn’t have sufficient privileges.”
I haven’t changed anything. Does anyone know what privileges it is referring to?
[It is also forcing me to run the game in administrator mode, which it never did before.]

Usually when a profile doesn’t have sufficient privileges, it means that the privacy settings on your Microsoft account are prohibiting Multiplayer things. Just go to the Microsoft website in a browser, log into your account, go to the privacy dashboard and make sure all the Multiplayer ones under “Xbox” are set to “allow”, particularly “Join multiplayer games”

However, it might not be related to that and may be a Windows or game issue. Do you run 3rd party security software like Norton, Avast, Kaspersky etc? Is so, try disabling it (you still have protection from Windows Firewall and Defender) as this game seems susceptible to this sort of software for some reason. Also the same if you use any sort of gaming software like Razer Cortex.