Pages Occasionally Appear Much Larger

Hello,

I am using the Mog Theme (with a child).
Almost every time I open a page, it briefly displays much larger than it should be before correcting itself.
Occasionally, it stays at this much larger size.
When I try to see what’s happening with Google Chrome’s Inspector Tool, it immediately corrects itself.
I’m not sure where to go with this. I’d love some help.

Thank you,

Dillon