Can't sign into windows store

I have restarted, restarted modem, flushed dns, signed in and out etc, also tried task manager fix. tried looking in windows store for updates, as per recommendation from another website. No luck. The mobile app can't install games, my other computer
can't install games, the windows store can't install games, and the xbox beta app can't install games. This is seriously broken and I haven't seen any effort from Microsoft to fix it

sign out of the store and xbox apps, sign in to the windows store and xbox app with the account that bought it, download it, then sign out of the store and xbox app and sign back in with your current account.

The Xbox App uses the MS store to do it's downloading. Make sure you are signed in on the Windows Store app the correct account as well as the Xbox app.

If you're signed in on Windows or the Windows Store with a different account that you use for ultimate it could cause some issues.

Family sharing on the Windows 10 PC is possible, but a bit more awkward than on the Xbox console where you just set the console as your Home Console.

While your brother can't download your Game Pass games himself, you can install them for him like this:

Make sure your brother's account is added to your Family at
https://account.microsoft.com/family

Then let him sign in on his Windows 10 Account on his PC.

Start the Windows 10 Store app, and sign him out of the store.

Sign in with your own account in the store app, and install the game(s).

After the installation is done, sign out of the store and let your brother sign in on the store again.

Be aware that you ONLY sign in on the store app. You do not need a complete own separate account on your brother's PC.

If you sign in on a separate account on his PC, your brother won't be able to access the games you install in your user area on his PC.

This unfortunately does not solve the problem. I have went to a complete reset of the PC, wiped the disk, download windows from the cloud, set up as new PC, and the error is still there. Can't sign into the XBox app, and the windows store says it can't download "XBox Identity Provider". Spent 90 minutes on the phone with support to no avail.