can't connect to games and parties

when i try to connect to my friends GTA 4 party game it says "can't connect to game session returning to single player"

Hi you should try uninstalling and reinstalling the app and see if that works. This happened to me before and i tried multiple things to get it sorted but only that helped it out. Hopefully it works for you too

Dear
ninjakat,

Kindly try these Solutions.

• Check the connection

Restart your PC and router.

Flush DNS.

Access Router settings and disable UPnP.

Disable VPN and Proxy.

Disable IPv4.

Use a wired connection.

Check the status of Xbox Live Service

• Install Teredo Adapter

Guide:https://windowsreport.com/teredo-adapter-windows-10-download/

• Check the permissions
  1. Press Windows key + I to open the Settings app.
  2. Choose Privacy.
  3. Select Microphone from the left pane.
  4. Under the “Choose which apps can access your microphone“, toggle on the
     Xbox app.
• Restart the app and the associated service
  1. Close the Xbox app completely.
  2. In the Windows Search bar, type Services and open Services.
  3. Locate the Xbox Live Networking service, right-click on it and choose “Restart” from the contextual menu.
  4. Do the same for the IP Helper service.
  5. Close Services and open the Xbox app again.
• Reset the Xbox app
  1. Open Settings.
  2. Choose Apps.
  3. Locate the Xbox app under the Apps & features and expand it.
  4. Click on the Advanced options link.
  5. Scroll down and click Reset.
• Change the default playback device

1. Here’s how to reset your playback and recording devices to factory settings:
2. In the Windows Search bar, type Sound and open Sound from the results.
3. Highlight the playback device, select the Advanced tab, and reset it to factory settings.
4. Repeat this for the microphone.
5. Save changes and exit.

Link:https://windowsreport.com/xbox-party-not-working/

restart the app or uninstall and install again

Have you tried with both mobile and wireless connection? same issue?