how to use the "Single turn Coil" in 3D?

hi everyone!

i want to use the component "Single turn Coil" to build Model for a flat inductor. At first i want to realize how this component work, so i have found a example from model Gallery. (the link is: www.comsol.com/model/single-tu...turn-coil-domains-in-3d-14067, single_coil_gap_feed.mph)

And then i build a identical Model depend on it, the parameters of Geometry, material and the component"single turn Coil"(including the "Gap boundary") is the same to the parameters of the example( the mesh is in default setting). But i get different results and the solution is not convergent in "Frequency Domain" study , if i set the frequency over thousands Hz.

i have cotrolled the setting many times, but just don't know the different between my model and the example. Can anyone tell me, what should i pay attention to? where will make a mistake?

thank you for your help!

ps. when the study of the example is running, there is some Information in the message box:
"Avoided 1 inverted elements by using linear geometry shape order."
I have never seen that, when my model runs, does it have relation to my problem?