Really quick question before I get into debugging this, in the sample scene there is it still making the "blip" noise as if text is reading out? I'm trying to figure out if this is a shader issue (text alpha not rendering on android) or a programming issue (text not rebuilding on android)
Also, if the debugger is connected, is it reporting any errors?
That example there already tells me the issue isn't Unity UI, since the bug is effecting both UI text and the non-UI text in my sample scene there, so that's good!