Place an item that animates on the screen. Go to the Item editor and select the same item you placed on the screen. Go to the second tab and click Test. The item you see animates quicker than the one you placed on the screen.
And when you go into Preview mode and turn on combo cycling by pressing C, the item on screen animates quicker.
Please fix it. Must animate normally while in preview mode and while testing the item in the item editor.