Otto has suggested a fix in Chrome itself until the bug is resolved:
- Go to chrome://flags/#disable-slimming-paint
- Enable the “Disable slimming paint” option.
- Ensure that the “Enable slimming paint” option below it is not turned on.
- Relaunch Chrome.
If you don’t want to take this approach you can fix this with CSS:
function chromefix_inline_css()
{
wp_add_inline_style( 'wp-admin', '#adminmenu { transform: translateZ(0); }' );
}
add_action('admin_enqueue_scripts', 'chromefix_inline_css');
If you just want a plugin to do it: https://github.com/raffjones/chrome-admin-menu-fix