It's just the first month in. I imagine that Trump has so much piled on his plate right now that that (ferreting out the leakers) is the least of his worries right now. I'm betting the issue will be dealt with, however, in good time. Just think about how much crap there is to deal with currently with the incessant whining, moaning, bitching and attacks coming from the left. It has to be a bit overwhelming. At least, it would be for me.
Oh, the first 100 days are going to be busy, for sure. (The more you sweat in training the less you bleed in combat).
But as far as the attacks from the Left, he should have anticipated all of that and more. The unexpected support that few acknowledge are the Conservative NeverTrumpers who are laying off and seeing what he is doing (AKA: being "fair"), still sticking to the same principles and goals they ever had, and giving credit where credit is due when he gets it Right.
It is hard to implement any strategy, though, in any adversarial relationship (such as Trump vs Press), when your punches are telegraphed, and that strategy is revealed to the press before you can even announce your intentions. Those leaks are subterfuge by bureaucratic holdovers who need to get a real job. They should be, from day one, one of the targets of the administration, and while a few moles will survive, most could be cleaned up and agency payrolls reduced at the same time. That's a two-fer, in most cases.
Trump is, as we are told, a businessman. I have run my own business, and when the opportunity presents itself to kill two birds with one stone (efficiency), you take it. I see that as a missed opportunity.