Endpoint /solutions/bookingBusinesses/$count returns 500 UnknownError

[h0s]

Describe the bug
The endpoint https://graph.microsoft.com/v1.0/solutions/bookingBusinesses/$count returns a 500 Internal Server Error with an UnknownError code instead of returning the integer count of booking businesses. This occurs even when the necessary advanced query headers are provided.
To Reproduce

1. Use an API client or graph explorer
2. Set the method to GET.
3. Use the URL: https://graph.microsoft.com/v1.0/solutions/bookingBusinesses/$count.
4. Add the Header: Authorization: Bearer <YOUR_TOKEN>
5. See error response: 500 UnknownError.

Expected behavior
The API should return a plain text integer (e.g., 5) representing the total number of bookingBusiness objects the authenticated user has access to.
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