Certain lowercase letters and punctuation cannot be typed into any text box on the bug tracker (the website you are viewing this report on) on mobile devices. This includes the search box, create issue, and everything else. This bug does not affect uppercase letters. A workaround for this bug is using slide to type or copy and pasting. The specific letters and punctuation affected by the bug are random each time you open the website. As far as I know, this bug only affects iPhone, but it may affect Android too.