If you are on Windows 10 Insider build, you may have been experiencing this issue for a while now. The clock & calendar flyout doesn’t appear when clicking on it. It’s confirmed as one of the known issues to the latest Windows 10 Insider builds and it’s been quite frustrating when not seeing it flying out when clicked.
Yani, what to do while waiting for Microsoft to fix it in the next build?
According to the Windows Experience blog, there is a quick workaround that you can use if you need the flyout to pop out when needed. All you need to do is to click either the Start menu or the Action Center icon right next to the click on the taskbar. You will see both appear at the same time but at least you will get to view the clock and calendar flyout.
I understand it’s not a permanent fix but still, hope it helps.