No matching rendered start form

Hi community,
I’ve face the problem that I could not retreive my rendered start form by the REST API.
The response body is showing the error message below.

{"type":"InvalidRequestException","message":"No matching rendered start form for process definition with the id ToolingWorkflow:72:857780ee-3c7e-11ec-a27e-005056be7ec1 found."}

I’ve uploaded my HTML form while the deployment of the process definition
image

<form role="form" name="form" class="camunda-form">
    <div class="form-group">
        <div class="form-row">
        <label class="control-label">Description</label>
        <input required
                type="text"
                cam-variable-name="myDescription"
                cam-variable-type="String"
                class="form-control" />
        </div>
    </div>
</form>

If I open an deployed task form, the response works fine.
As well If I start the process in the Tasklist of the Camunda Webapp, It works perfect.

Has somebody any idea.

Thanks for the support

Michael

Just an addition: If I declare the form directly in the modeler, the rest call works well.