Potential Bug: Page Header Image Overblown after Refresh

Hi,

Here is what I did: on a post I set the page header to have an image (dimension: 1000px-500px; hard-crop: disabled) and included the content in form of a <h1> text, telling it to use the image added from the previous tab as the background and have it presented fluidly, in full-screen, and with vertical centering.

So far all was fine and the page header appeared as it was meant to. The bug kicked in when I positioned my browser screen with the Page Header as its center and then refreshed the page. What happened was the page header with slightly zoomed-in background image and increased size of the top and bottom padding of the h1 content in the page header. When I refreshed the page again, the page header zoomed-in even more and the padding became ridiculously large. Subsequent refreshing result in larger image and padding. The only way to resolve this was to go to the top of the web page and refresh and then the page-header would go back to its original size.

I am guessing that this was not an intended behavior and wonder if there are any ways of sorting it out.

Thanks
Maziar

Note: my browser is Chrome.