Graph API returns an empty array when getting events by iCalUid or uid which worked fine in June 2026

Question

When we make a request like this

https://graph.microsoft.com/v1.0/users/{user}/events?$select=id,subject,responseStatus,iCalUId,uId&$filter=uid eq '{uid}'

or like this

https://graph.microsoft.com/v1.0/users/{user}/events?$select=id,subject,responseStatus,iCalUId,uId&$filter=iCalUId eq '{iCalUId}'

response is empty.

{

"@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('useremail')/events(id,subject,responseStatus,iCalUId,uId)",

"value": []

}

I can clearly see there are values and able to see data without $filter and clearly see the iCalUId and UId i am using in the data list.

Exact same filter query using iCalUid used to worked perfectly on 29 June 2026, what could be the issue? what are alternatives to find the responseStatus for an event?

Note: I am directly making rest calls from Bruno. no API or library updates...