No sound in Apple TV+ Through HDMI

Hi!

as I do not own an Apple TV, but I want to watch the shows on Apple TV+ on my tv, I purchased a usb-c to Hdmi adapter for my iPad Pro so I can connect it to the tv.

The Hdmi adapter is working perfectly, and it even recognises when I am playing a movie, but unfortunately, when using the Apple tv+ app, there will be no sound coming out either from the tv or from the iPad.

Weirdly, this only happens with the Apple TV+ App, with Apple Music, Netflix, Youtube, Amazon Prime etc.... sound and image come out perfectly from the tv, therefore it can’t be a Hardware Problem.

I also checked if the app was on mute, but it wasn’t....

Has anybody here experienced the same problem? Or, has somebody been able to get sound from the Apple TV+ app through an HDMI?

Thanks a lot! :)