Hi there,
we aim to reply to every support topic within 24hrs, our average response time is below 5hrs. If you can afford us a little patience when waiting for a response.
Just to be clear, in the Post Editor – is the Content Title field missing or just un-editable ?
Either way this is a core function not a theme level function.
First to check – are you using a Child Theme ? If so try disabling that.
If not – please check for plugin conflicts by temporarily disabling all other plugins apart from GP Premium.