So, I'm in the final stages of alpha for my sudoku app (only like 4 more bits of feedback to work on and it's done! woo, finally!), and one of the bits of feedback from my testers is that some of the text has weird spacing to it. I confirmed with everyone in the test program that it was all there and not a device specific issue, and found out everyone had it. Basically, with some of the words throughout my app, the text has weird spacing between letters, and while it's not huge, it is noticeable and a bit annoying, especially once you notice it

I've uploaded an album here and highlighted a few words that have issues. As you can see in words like option and separately, there's more space between the op, ti and on in option, and same goes for the se, pa, ra, tely parts of separately. It's a bit of an annoyance, and I can't seem to find any way to fix it. Has anyone experienced this before, and if so, is there an easy fix?
Many thanks!