Bought a new pre-seasoned cast iron and not sure if seasoning is good
I've seen similar things on a couple of pre-seasoned pans (one of them a Lodge). My suspicion is that the uneven heating of the pan leads the seasoning in one area to burn, while the other area completes the polymerization that began during pre-seasoning. 

The number one thing that people do wrong with cast iron is worrying too much about the seasoning. Seasoning will basically just happen eventually; manually seasoning the pan is just an optional means to shortcut a longer period of natural seasoning through cooking; actual problems with the surface (rust, caked-on carbon, and... I think that's it) are thoroughly obvious.

Seasoning is as seasoning does. A cast-iron pan will never be as non-stick as a teflon-coated pan, but it should display superior food release compared to a bare steel pan. So just... cook with the thing. Differences in shininess should be ignored; differences in stickiness should not be.