Bluetooth keyboard

I'm assuming you've checked power on the keyboard and that it is Connected to the iPad.

Are there any specific keyboard combinations which aren't working for you?

I found I have to use the Mac keys on my keyboard rather than the Windows one for the combinations to work.

For example Ctrl + Z does not work but Command + Z does. As indicated in the Keyboard shortcuts link.

All other single key shortcuts seem to work fine on my system.