In the Calendar, opening or closing the settings introduces the scollbar for a second so the + New event and other buttons shrinks a bit for a split second.

Having overflow-y: hidden; would fix the issue but it looks like it is set to auto explicitly. Was that intentional? Maybe add the overflow-y as a configurable prop in case an app wants the scrollbar?
I can make the PR.
cc @skjnldsv @georgehrke
Sorry, I fall over my keyboard. What I wanted to say: you can't know if your navigation is longer than available room. Hence overflow must be auto. The issue has to be solved using another fix.
@gary-kim Does removing the height: 100% on the ul fix your issue? Could be it doesn't need to re-render the 100% then...?
Edit: Just recognized i can check that on my own. 馃う鈥嶁檪 It doesn't solve.
Most helpful comment
Sorry, I fall over my keyboard. What I wanted to say: you can't know if your navigation is longer than available room. Hence overflow must be auto. The issue has to be solved using another fix.