$odata.count = -1!?
I'm experiencing same issue as https://github.com/microsoftgraph/microsoft-graph-docs/issues/3848 with some tenants - but not all.
Query:
/v1.0/me/mailFolders/<id>/messages?$filter=isRead%20ne%20true&$count=true&$top=10
Response:
Clearly there are 10 or more mails, but $odata.count is -1. This means that proper pagination is not possible to implement and I'm fairly sure the API is broken. What triggers this is beyond me, since same code works for some tenants but not others. It could appear that the issue is related to the $top and having more than this matches, but not sure.