Hi Sundance,
In general I’d imagine that H264 encoded RTSP streams should work just fine on most android devices - so I’d recommend that encoding.
I assume you are familiar with this guide? : Stream CCTV IP Camera in to Xibo for Android
So basically all your devices are giving, canRun errors, unsupported video (encoding), then they are blacklisted and whole layout is invalid.
Questions:
What apk version do you use? (and why not R59? 
)
Are there general problems with various videos on your devices?
When was the last time you updated the firmware? (especially on android box)
I also had a look at your previous topic about streams, it seems that you still have similar problems.
Basically if the stream is correctly set up with the right encoding (H264) it should work just fine, if it doesn’t I’d slightly lean towards hardware issues - which could be resolved with newer firmware.
Unfortunately I didn’t have the pleasure to use any of the devices that you have, so it’s hard for me to give you definitive answer here.