Empty Palyoad for data to https server

Have a TRB246 and try to send GPS data with “data to server” to a https server.
I see the http request on server side, but the payload is always empty.
If I enable the HTTP/HTTPS server directly in the GPS menu, i get a lot of data. But here i can not select what values i would like to send. But the server side is working.
I can also use “data to server” with server type MQTT, which is working. But with HTTP i never saw any paylod. Used Format type is JSON.