If it’s a “blue gene” Jack Dempsey it isn’t the same as an Electric Blue Jack Dempsey (EBJD)
A Blue Gene is the offspring of one EBJD and a regular Jack Dempsey, and will have normal coloration and you’ll be able to sex it by the bearding most times.
If it is an EBJD then sexing will be quite a bit more difficult, some people say it can be done visually but I can’t do it. And have seen cases where people swear to the sex then end up wrong.
Either way, Jack Dempsey’s period can be very shy, I’ve seen lots of them be what I like to call “cave warriors “ and simply pick a cave or hide spot, and simply defend it. Only coming out to eat. Then I’ve seen very personable JD’s so really it can go either way. Yours sounds young, and also new to your home. So give it time and it will come out of its shell, or it won’t.
duanes
made a great point. Maybe a top column species would help it break out of its shell.
Post a picture and we may be able to help you determine sex.