OneDrive personal: SharePoint sign-in handoff fails, "Shared with you" empty while own files work (recurring)

Consumer OneDrive account on a Microsoft 365 Family subscription. The SharePoint layer serving the account appears to be failing while the consumer OneDrive layer works normally. Looking for anyone who has seen this pattern, or who knows how to get it escalated.

WHAT WORKS

"My files" loads normally, all folders visible, signed in with avatar showing. Under Shared, the "By you" tab lists everything I have shared out, complete and correct.

WHAT FAILS

Under Shared, the "With you" tab is completely empty. No items, no error message.

Clicking "Shared" redirects to login.live.com, then to onedrive.live.com/_forms/default.aspx?apr=1&wa=wsignin1.0 (the SharePoint sign-in handoff endpoint), which returns "Something went wrong. This is a temporary issue, so try again in a few minutes." Ref A: 975E18880ADA4BDFA5B0781EFFA74425 | Ref B: SG2EDGE1921 | Ref C: 2026-11-13T04:34:42Z

Requesting the SharePoint-rendered view of my own drive (/_layouts/15/onedrive.aspx) does not render; it bounces back to the OneDrive home page.

After the failed handoff the whole session is dropped and the page shows "Sign in" again, even though I was signed in seconds earlier.

Console output during failures: "GetDataError: Attempted to perform an unauthorized operation" and GraphError, both from odcfiles.js.

Later the same day the home page itself began throwing "Failed to fetch", and the settings menu lost all options except the theme selector.

ALREADY RULED OUT

Subscription: Microsoft 365 Family renewed successfully on 07 Nov 2026, active through 06 Nov 2027.

Storage: 1 TB entitlement intact, well under quota.

Family sharing: account confirmed still listed as an active member.

Authentication state: signed in successfully, own files accessible.

Anything client-side: reproduced on a second machine, which rules out cookies, cache, extensions and browser settings. Also reproduced in both Chrome and Safari on macOS.

RECURRENCE

The same class of failure hit this account in September 2026, also at SharePoint endpoints, also with SG2EDGE reference codes.

Ref A 6804F61AC9904D6EA100B531C98EC670 | Ref B SG2EDGE3722 | 2026-09-14T08:06:16Z

Ref A 56FEA2F6DE994FB3BCDBF2D107D3722F | Ref B SG2EDGE2309 | 2026-09-14T08:15:01Z

Twice in two months on the same account, always at SharePoint endpoints, always from the Singapore edge. That reads like a persistent provisioning problem on the account's SharePoint side rather than a passing outage.

QUESTIONS

Has anyone seen the _forms/default.aspx handoff fail persistently for a consumer OneDrive account?

Is there a way to force a reprovision of the SharePoint side of a personal OneDrive?

What is the most reliable route to reach an engineer for this? Phone and chat support are currently showing as unavailable, and the Support Assistant loops back to self-help articles.

Environment: Chrome and Safari on macOS, accessing from Vietnam. Reproduced on two machines.