Game pass pc games unable to sign in with error 0x80070520

Exact same issue.

Login to the store is fine, but the separate login for games fails.

I did try this a week ago and it didn't work for me.

I just gave it another try and it still doesn't work.

Authentication from within games still fails, for example in Grounded: Xbox Live popup appears, I click on my account and the login fails with the above error code.

Login in every other Microsoft service works without a problem: Windows, Office 365, Outlook, and even this damn Xbox app.

Really the only thing you can do and what is recommended is that you
continue insisting with the Xbox team, explaining the situation in detail
since they are the only ones who can help you because they do have access to
the accounts and can see what possibly happened. . This forum is really not the
most appropriate medium to discuss your topic, especially since we as players do
not have the tools to help you as it is a sensitive privacy and security issue.

Below I will leave you the link so you can contact Xbox technical support:
https://support.xbox.com/contact-us

Note: Remember that Xbox chat is open Monday to Friday from 9:00 a.m. to 5:00 p.m. m. to 9:00 p.m. m.

I used this https://support.xbox.com/en-US/help/games-apps/troubleshooting/gaming-services-repair-tool and it worked

No, nothing.

Reinstalling Windows to fix a broken gaming app is simply not an option and neither is using a new Windows account which is also hours of work until everything is installed / copied / configured.

It's simply ridiculous that they use some obscure Windows configurations or services that nobody can easily identify / fix and that rather consistently break the Xbox app.

That's on top of Microsoft breaking the app from time to time themselves, like a few months ago when games were not installed to the configured install location for some time.

I am about to give up on this stupid Xbox app and cancel Gamepass despite being a subscriber since day 1.

I only play 2-3 games on Gamepass per year anyway, so I could just buy them on Steam, which pretty much always works, as do Epic and GoG.