Its probably bug fixes. I face issues that I haven't seen anyone post, such as my phone hanging on the caller screen when I get a call, then if I tap accept reject or whatever it just doesn't work, neither do the capacitive buttons. Only resolution is hit the lock button, which silences the phone and see if you can accept then, if not then you gotta hang up the call by hitting lock button again or just don't answer(because you can't). After locking its normal again.
It happens rarely, but it has happened more than thrice so far. On stock btw.