Content sharing not working in a conference with UCMA 5.0

I've developed an UCMA application (using UCMA 5.0) that basically creates an ad-hoc conference and then joins it as a trusted participant (for recording purpose). After that, it adds some participants.

The problem is that the content sharing options are not available. From the tests, I've seen that the content sharing options disappear when the trusted application joins the conference.

Is there a way to avoid this and permits the content sharing inside the conference?

Thanks.
Gianluca