Version: 51.0.2704.106
OS: Linux

What steps will reproduce the problem?
(1) Enable scroll anchoring in chrome://flags
(2) Go to https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Using_CSS_flexible_boxes
(3) Scroll down slowly until the viewport top is at the first paragraph

What is the expected output? What do you see instead?
There's about a half second of flickering where it looks like the page goes back to 0 and the current scroll offset.

Presumably this is the known problem with sticky type bars but you may want to confirm/collect broken pages.