calendarView/delta returns identical event pages indefinitely — $skiptoken rotates on every response, @odata.deltaLink never emitted

Hello, a specific user's Microsoft Graph calendarView/delta cursor is wedged. Every paginated response returns an identical 278-event set with a fresh @odata.nextLink, but @odata.deltaLink is never emitted, so pagination cannot terminate. We've ruled out our pagination logic, date-window size, and request thresholds; behavior persists across thousands of consecutive requests for one user while other users in the same tenant sync normally. We need help understanding the server-side cause and resetting the cursor.

I posted earlier with the same title, but for some reason, it was auto-deleted. The link is https://learn.microsoft.com/en-us/answers/questions/5883982/calendarview-delta-returns-identical-event-pages-i