at the top of my ipad there is a lock showing

iPad Air2 does not have a configurable side-switch that controls the Screen Rotation Lock.

To enable or disable Screen Rotation, you need to access the Control Centre. Swipe downwards from the top-right corner of the screen - then tap the Screen Rotation lock icon:

More information about the Screen Rotation Lock can be found here:

Rotate the screen on your iPad – Apple Support

For information, if screen rotation proves to be problem with some Apps - and not others - you need to be aware that not all Apps are coded to operate in both Portrait and Landscape screen modes. Apps that have a fixed screen orientation will always appear in the orientation determined by the App Developer.

I hope this information and insight proves to be helpful in resolving any problems.

The lock symbol with a circular arrow simply means your screen is locked and will not rotate when you turn your iPad. It can be locked in either orientation, portrait OR landscape. You may have moved the slide switch on the side of the iPad. That switch is usually set to lock screen rotation.