HTML5 rendering in Google Chrome changes based on window size

Lighting renders correctly in Firefox and Edge
Depending on the size of the window in Chrome though, the lighting switches between normal and a much brighter version of the same.

I’ve been messing around with the generated CSS canvas element with no joy.
Does it have something to do with -webkit-box? Or the Blink rendering engine used by Chrome?
If someone could point me in the right direction pls, so I don’t cri evrytiem

Some project settings:

Shipping build

Plugins disabled

Use Pak File

Default heap sizes (1024)

Preserve Aspect Ratio enabled under Project Settings - Description

Allow Window Resize disabled under Project Settings - Description

Downloaded Opera there to check it out and it ONLY shows the lighter version…
Opera also uses Blink.