what versions of the operating system on each tablet, and what stream are you trying to watch?
if you’re watching a stream with high/medium/low quality options, it should always work on your tablets,
if you’re trying to watch a stream on the “source” quality, it won’t work on android 4.4
I’m under the impression that this is because the video technology (RTMP) is based on flash, and as you might know flash is nonexistant on android 4.4