[QUESTION RIGIFY] Does anyone knows why rigging works different in metarig and rig, in the neck area?

Hello. I've practising with Rigify. I have detected a misbehaviour (I think).

First, I place the METARIG the best I can, and I make a quick test binding (automatic weights) a mesh to it. If I move the neck area, everything is good.

Then if I detach the mesh, I create the RIG, and I bind the RIG to the mesh (automatic weights), when I make the exact same pose in the same place, a bad deformation happens.

If I select layer 29, and its bones and proceed to weight paint mode, I can see that both, METARIG and RIG has the same weights. So I don't think this is a matter of weight painting?

And advancer rigger knows how to fix this? THANK YOU!