Menu flashes on hover for windows on multiple screens resolutions

Summary

If a window is stretched across multiple screens at different resolutions, hovering the menu produces a flashing effect.

See Gif in related tweet https://twitter.com/Ben_EastRBLX/status/1138836367004319744

Steps to reproduce

This requires an operating system that allows windows to span multiple screens. Mac's do not allow this. Able to reproduce on Windows.

1. Monitor A is arranged to the right and has a resolution of 1920x1080
2. Monitor B is arranged to the left and has a resolution of 3840 x 2160
3. Open a window on Monitor A on any page in GitLab (Example /issues)
4. Drag the left side of the window onto Monitor B so that it spans both monitors and changes to the new resolution of Monitor B
5. Hover the menu over the subtitles of the page (Those in grey, for /issues those would be List, Boards, ect)
6. The menu will flash.

Refreshing the page or navigating to a new page stops this flashing from occurring.

The reverse of this also works, starting from spanning the 2 monitors and dragging the left side of the window to the right so that the window is only contained within Monitor A.

Example Project

Appears to happen on any project. Tested on gitlab.com

What is the current bug behavior?

Flashing menu on hover.

What is the expected correct behavior?

The menu should not flash when hovered.

Relevant logs and/or screenshots

See Gif in a related tweet https://twitter.com/Ben_EastRBLX/status/1138836367004319744

Output of checks

This bug happens on GitLab.com