So, there are a few solutions I can think of. Nor is that glyph included in any of the default assets. So the i becomes İ, which doesn't have a corresponding glyph in the text asset.
ToUpper() is called without much thought as to culture. I think the issue is that when you use the SC tag. I actually can't recall what the letters stand for, but the SC tag is the one that displays all characters as uppercase versions of themselves, but the characters that were previously lowercase are smaller. Another developer (or at least hobbyist), awesome! In that case, I can get a bit more technical :)