mf and mef huge difference

Hi,

I want to compare mf and mef physics in order to know which one I have to use for my study.
I work with a coil and a conductive core. I'm interesting in the electromagnetic power dissipated in conductive elements mf.Qh and mef.Qh respectively.
Under same excitation set up (current surface like in cold crucible tutorial) I obtain a huge difference between values of dissipated power in the core: mf.Qh=12.14 kW and mef.Qh=3.7 kW
Mesh is the same for the 2 physics and increasing mesh density has no significant impact on results.

Magnetic fields seems to be very different in the 2 cases, i join a picture of streamlines

I attach as well my simple model.

Can someone can explain this huge difference?

Thank you