EWS request does not work anymore after upgrading from a manifest.xml to a manifest.json

[b521f771d8991e6f1d8e65ae05a8d783]

manifest.json

"authorization": {
        "permissions": {
            "resourceSpecific": [
                {
                    "name": "Mailbox.ReadWrite.User",
                    "type": "Delegated"
                }
            ]
        }

taskpane.ts

// some other code
function testButtonAction() {
  const from = new Date(Date.now() - 1000 * 60 * 60 * 24 * 7 * 50);

  const query = `<?xml version="1.0" encoding="utf-8"?>
              <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
                            xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
                <soap:Body>
                  <FindItem xmlns="http://schemas.microsoft.com/exchange/services/2006/messages"
                            xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"
                            Traversal="Shallow">
                    <ItemShape>
                      <t:BaseShape>AllProperties</t:BaseShape>
                    </ItemShape>
    
                    <Restriction>
                      <t:IsGreaterThanOrEqualTo>
                        <t:FieldURI FieldURI="item:DateTimeReceived" />
                        <t:FieldURIOrConstant>
                          <t:Constant Value="${from.toISOString()}" />
                        </t:FieldURIOrConstant>
                      </t:IsGreaterThanOrEqualTo>
                    </Restriction>
    
                    <ParentFolderIds>
                      <t:DistinguishedFolderId Id="inbox"/>
                      <t:DistinguishedFolderId Id="outbox"/>
                    </ParentFolderIds>
                  </FindItem>
                </soap:Body>
              </soap:Envelope>`;

  if (Office.context.mailbox) {
    Office.context.mailbox.makeEwsRequestAsync(query, (result) => {
      console.log(result);
    });
  }
}
// some other code

Error Message:

Für den Aufruf der Methode 'mailbox.makeEwsRequest' sind erhöhte Rechte erforderlich.
    at K (https://appsforoffice.microsoft.com/lib/1.1/hosted/outlook-win32-16.02.js:20:209005)
    at te (https://appsforoffice.microsoft.com/lib/1.1/hosted/outlook-win32-16.02.js:20:210370)
    at e.$e (https://appsforoffice.microsoft.com/lib/1.1/hosted/outlook-win32-16.02.js:20:229102)
    at HTMLButtonElement.testButtonAction (https://localhost:3000/taskpane.js:3804:28)

(the error message ist German, a translation would be: "Elevated rights are required to call the 'mailbox.makeEwsRequest' method.")