- Have you tried using the Repair or Reset option to find if that makes it possible to uninstall ?
Uninstalling the XBOX app should prevent the UI from trying to connect.
- Open Powershell (admin mode) and cut and past the command below to uninsatll\disable XBOX App
Get-AppxPackage *xboxapp* | Remove-AppxPackage
- There are several other XBOX related apps that can be removed along with a lot of other Win10 Bloatware.
.... Lifted from - Uninstall Apps in Windows 10 Windows 10 Apps & Features Tutorials
- Xbox Console Companion [ current account only. There are other options for all accounts in the article above ]
Get-AppxPackage *Microsoft.XboxApp* | Remove-AppxPackage
- Xbox One SmartGlass
Get-AppxPackage *XboxOneSmartGlass* | Remove-AppxPackage
- Xbox Game Bar
Get-AppxPackage *Microsoft.XboxGamingOverlay* | Remove-AppxPackage
- Xbox Game Speech Window
Get-AppxPackage *Microsoft.XboxSpeechToTextOverlay* | Remove-AppxPackage