First of all, I somewhat recently switched from Chrome to Firefox on my Android mobile. And that was solely due to Chrome's continuous bad updates which ruined the UI. Well an issue arose today whilst I was attempting to access my work email, I couldn't type in my username or password. In fact it appeared I couldn't type anywhere, on the Google home page, nowhere. YouTube, Chrome, and rest worked just fine, only Firefox had this issue. So that ruled out something being wrong with the phone itself. Restarting my phone 'fixed' the issue, though I wouldn't like to use the word fixed as I have no idea why it occurred in the first place, therefore I must assume that it can very possibly occur again. I'd rather have it not.