A delay doesn't have to be because of issues with your own case. Even for people fast-tracked because of a job offer, the COs will be working other, similar cases in rotation, so maybe he got held up on an issue with one of those, meaning he's only just got to yours. As he now says he's looking at yours, and you're sure you've sent everything necessary, here's hoping it goes quickly from this point on.
('They say three months with job offer' - ALL the timings mentioned by INZ have to be seen as guesswork based on recent averages, because there is possible variation of how many cases come in at once, how complicated cases are, and working conditions, e.g. sick leave or people leaving, in the office.)