I am having the same issue.
I downloaded the Infuse app, I paid for the Pro version, I connected to my Good Drive account using the Cloud Service feature, I found the video I wanted to play, I started playing it, I then switched the output to be the AirPlay output to my Roku SmartTV.
When I did I got the audio portion playing through my TV, but the video portion remained playing on my iPad, and on my TV, I just got an album cover type look with a musical note on it, and the title of the video scrolling below it.
I have no idea what I need to do in order to get the video portion to also play through the TV.
I will say that I tried many other methods and nothing I tried could ever get any output to go to my TV. As soon as I would try switching from the iPad to the TV, the playback would simply stop.
Infuse is the first playback method that didn’t simply stop working.
So, although it only got the audio working so far, and not the video, it is farther that any other app/streaming/air play/etc method so far, so I have more confidence in it finding a solution than anything else.