FHIR search with occurrence parameter fails for Timing

Question

I'm trying to find all ServiceRequests (in my Azure FHIR Service instance) that end before a given date. Some of my ServiceRequests.occurrence have a Timing instance and others have a dateTime instance. When searching with the "occurrence=eb{date}" the search doesn't pick up the ServiceRequests with a Timing instance. The search works fine for ServiceRequests with a dateTime instance.

Any idea what the issue might be with my search query?

For example, if I perform this search without the occurrence parameter:

{{fhirurl}}/ServiceRequest

I get the following result:

{
    "resourceType": "Bundle",
    ...
    "entry": [
        {
            "fullUrl": ...,
            "resource": {
                "resourceType": "ServiceRequest",
                ...
                "occurrenceTiming": {
                    "repeat": {
                        "boundsPeriod": {
                            "start": "2024-08-27T08:00:00+02:00",
                            "end": "2024-09-10T07:59:59+02:00"
                        },
                        ...
                    }
                },
                ...
            },
            ...
        },
        {
            "fullUrl": ...,
            "resource": {
                "resourceType": "ServiceRequest",
                ...
                "occurrenceDateTime": "2024-08-27T08:00:00+02:00",
                ...
            },
            ...
        }
    ]
}

But when I add the occurrence parameter

{{fhirurl}}/ServiceRequest?occurrence=eb2024-09-13

The search comes back without the instance that has a Timing instance:

{
    "resourceType": "Bundle",
    ...
    "entry": [
        {
            "fullUrl": ...,
            "resource": {
                "resourceType": "ServiceRequest",
                ...
                "occurrenceDateTime": "2024-08-27T08:00:00+02:00",
                ...
            },
            ...
        },
    ]
}

Any idea what the issue might be?

I've also tried using "le" and "lt" instead of "eb" as a date prefix, without success.