few view controllers are looking large when size class is enabled?

I am facing a very big problem with interface builder in Xcode .I am have used size class 'Width Regular,Height Compact' for iPhone in landscape mode.It was all working fine but suddenly it all messed up. I am facing two problems Whenever i change the size class to 'Width Regular,Height Compact'(iPhone Landscape) then i face these problems

• ViewControllers in width looks very large.
• Constraints are not updated properly.Whatever constraint i set it does look as it should be.

ScreenShot:Previous iPhone 5s preview ViewController:

ScreenShot:Now iPhone 5s preview ViewController(too large)

Please help me in getting the solution.