It is hard to know, but it kind of sounds to me like it might be the setting in your text components for vertical and horizontal overflow. Try setting those to Overflow instead of wrap and see if you get different results in the build. It could also be the anchor points. Make sure your Canvas Text objects have the anchor points set right at the corners of their bounding boxes. And make sure your canvas is set to scale with screensize.
Hi, thanks.
I did mention I had tried setting the overflow:
> "I've set my text fields to display Unicode as well as have both vertical and horizontal Overflow. "
However I found the source of the problem. It was in the way Unity is packaging JSON files, which get assembled weirdly on build, so much so that a filepath in one's JSON parser can't access them. I moved it into Streaming Assets which are left alone on build, the parser could read the file and the text set itself fine after that.
Thank you for the response.