I can see exactly the same bug in MuseScore (soft based on QT).
When you want to drag an element on the left panel, Unity panel appears and don't want to hide itself.
If I want to hide Unity's menu I have to open an other soft and drag something (like an image in Firefox). After 2 or 3 seconds, Unity's panel auto-hide normally.
OSW
P.S. I'm very very very sorry for my bad english, I'm young and I'm a very bad student :)
I can see exactly the same bug in MuseScore (soft based on QT).
When you want to drag an element on the left panel, Unity panel appears and don't want to hide itself.
If I want to hide Unity's menu I have to open an other soft and drag something (like an image in Firefox). After 2 or 3 seconds, Unity's panel auto-hide normally.
OSW
P.S. I'm very very very sorry for my bad english, I'm young and I'm a very bad student :)