Seeing similar behavior. On device, just returns back to Home Screen after either the spinning loading circle or the ad plays. On the online Roku Channel, just loads black screen, no video, no audio.
I haven't come across anywhere else that it is playing for free.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102