Not able to connect to parties through game bar or companion app.

This solution doesn't work. I am having the same issues. Before this new windows update I was able to receive party notifications through the companion app. Now I cannot recieve them through the companion app or the game bar. I guess it should be noted
that you CAN invite people to a party from the companion app and they can join. But for whatever idiotic reason you cant recieve the invite.

I updated and notifs are enabled, still no party invited through companion app, I only get them through game bar

Thats what I'm doing.. the only thing I am doing different from playing keyboard/mouse is the controller itself. but when i plug it in every setting on the pc changes to controller mic. Even though the controller has no mic. So I go back through all the
pc settings and xbox companion settings and change it back but the xbox game bar will not let me use the usb mic anymore. I have to unplug the controller and reset the pc to be able to use my mic again. when I start a party in the companion app it says my
mic is working , but if i am in a party on that app for some reason I'm not in a party on the game bar... so if i start a party on the game bar the mic still doesn't work..

If you have the latest update, then party invites don't go to the Xbox Console Companion app anymore, and they go straight to the Game Bar. Same for party chat on the PC.

To access the Game Bar, just press the Windows button and G at the same time, you should be able to see your invites there.

Have you tried using the Game Bar in Windows 10? You can activate it by pressing "Win+G" buttons. I've been able to join my friends on Xbox parties through there. I haven't tried using the Console Companion app, so can't say if that's worked for me or
not.

Is your friend also on PC?