This is a good one.
How is it possible that the same header can display in different ways at the same time? Occasionally, and without any provocation, my header will go crazy in one window as I reduce the viewport - while in a separate window it behaves like the well-trained pet I always wanted.
As you can see from this screen grab, these two windows displaying the same page and produced concurrently look very different…
The window on the right is behaving sensibly while in the one on the left the logo has shrunk, the search bar has dropped and the slider and page content have risen into the space vacated by the shrunken logo. Also, the 3-bar menu works in the window on the right but doesn't respond to mouseover or mousedown in the window on the left (although the Search field accepts input in both versions).
Needless to say, this is the same page with the same code and the same content - rendering in two different ways at the same time. The phenomenon affects all pages
The logical side of my brain says this is impossible. But it is happening and I hope a superior being can tell me why. TIA