HTTP Request - error after update

[pfischer]

Hello everyone,
we use the flow element "HTTP Request" and send a POST command with parameters to a server.

After switching from Switch 2019 to Switch 2024, this imported flow no longer works. The server apparently cannot recognize the parameters, only receives an empty POST command and returns an "Invalid Request". Switch logs "Method not allowed" and "Status code 405" in the log.
What has changed in the flow element or do we need to adjust our parameters?

We have downgraded the HTTP request element to version 15 via the App Store, so the request runs. From element version 18 we get the error.

Thank you very much for your help.

Peter