Hens, plain and simple. Especially if you are having this experience right around fly down.
Here is what is happening IMO, bird is blistering it on the limb, then on the ground right when he lands. You call, he is eager to join his hens, and starts to head towards you. In the meantime, the hens join him along the way, he struts away with them. Hence the shutting up and disappearing.
COuple of ways to beat it, set-up close, I mean push the envelope close to him on the roost. Call sparingly, we all love to hear them gobble, but that just adds to the problem of him drawing his hens to him. Be close, and that will allow him to come find you first before his hens intercept him.
This is pretty common right now when things start greening up, many times the hens will quiet now, and with a little foliage he can't see them like he could a week ago. Or they are roosting separate, but it is a little early for that yet.
Remember, don't overcall!!! Making him hammer a million times on the limb or on the ground will only hurt you in this phase.