I have seen this kind of behavior after upgrading my own systems before. It is usually resolved after a browser cache clear and refresh of the screen. Can you try this? Or ctrl + F5 in chrome to refesh cache?
Hi, do you happen to have a fresh install (not an upgraded one), if so, I suggest compare the css between working and broken and see if you find anything obvious. If it does not help and continues to be an issue, you may enter a support request and we can investigate the issue further. Thank you