Graph API, search for driveItems: general exception, 500 internal error

Hello,

I am trying to use the graph api via HTTP calls to search for items in Sharepoint drives of a specific site, based on their name, but I'm getting a 500 internal server error as a response, with the following body:

{
    "error": {
        "code": "generalException",
        "message": "General exception while processing",
        "innerError": {
            "date": "2023-04-26T08:14:26",
            "request-id": "{request-id}",
            "client-request-id": "{client-request-id}"
        }
    }
}

I followed the instruction on that page to build the request: https://learn.microsoft.com/en-us/graph/api/driveitem-search?view=graph-rest-1.0&tabs=http.

I am sending a simple HTTP GET request: https://graph.microsoft.com/v1.0/sites/{Site-id}/drive/root/search(q='{filename}'), with a Bearer token generated for an application user.

That application has Site.Selected as API permissions, and I can create folders, upload items or download items without any issue on that same site. (so I suppose it is not related to a permission issue).

Would you have any idea why I get that error, and what I'm doing wrong? Is there a config that should be changed or verified in Azure to make it work?

Thanks a lot for your answer :-)