Qt Designer hands when draging a menu item

Hi,

Today, I wanted to move a new menu item in application menu, Qt Designer interface hung up for some minutes, but my item is still at the same place as before and can't be moved.

I made a little video to show what happens, I tried to move the menu item "Logs directory" at the front and the interface was blocked and I couldn't click on anything. 3 minutes later, the interface was responding again.

Thanks