With Qt Creator 4.10.1, I am experiencing the issue that the UI sometimes is frozen after unlocking my mac book (waking from sleep).
It happens maybe in 25% of the cases. I couldn't see a pattern yet.

However, the symptom is quite interesting:
The UI behaves like it would be an image. So if I resize the window, the UI is shrunk and stretched like an image and the "content" doesn't change anymore.
For example, in the following image I shrunk the window:

Note that the text in the window's title bar is perfectly readable, so it is not the screenshot which is distorted but it is really Qt Creator's UI.

Qt Creator itself is still working. For example, builds continue to run and I can still interact with the main window menu bar. Also the mouse cursor changes when moving over the UI. But the UI simply doesn't update anymore.