I'm having a problem with a fixed position element in mobile Chrome. A little gap between the fixed top element and top of the viewport appears when I swipe up and down without reloading the page.
To replicate this bug the easiest way is to try the bootstrap example https://getbootstrap.com/examples/navbar-fixed-top/ in mobile Chrome. Swipe up and down without reloading page and after few tries you should see a gap.
The most common answer on Chrome rendering issue. Fixed position anchor with UL in body does not work for me:
#element {
-webkit-transform: translateZ(0);
}