I am testing your free trial and is working fine. It is working in an Android TV (Sony-KD-65XE9005) fine. But after a while, the video stops and the TV changes to the TV input that has configured. In my case, it shows the input of the HDMI1.
Have you detected such way of work with another Android TV?
I have not tried that specific TV but the TV variant of Android does not work well in general. I suggest that either you use an external TV box that has the tablet version of Android installed, running Android v7 or later, and that you make Video Kiosk the device owner OR that you hide the standard Android TV launcher as described on page 54 of the Users Manual so that it can never appear: