I’ve been struggling with getting text input and timers to work and not knowing why only certain characters showed up. Finally I asked someone, and was told that I had made one of the most simple of mistake to make without realising it.
I had not embedded enough characters in the font I was using.
To fix it, all I needed to do was re-embed the font, selecting more characters to include. So simple, yet so so easy to overlook. Let’s hope I don’t do that again.