Keyboard shortcuts not working with iPad connected to External Display

I cannot use keyboard shortcuts when my iPad is connected to an external display. Specifically, I want to use cmd-tab to switch between applications and cmd-space to pull up spotlight search. They work fine when the external monitor is not connected.

I have a full-size Apple Magic Keyboard as well as an Apple keyboard folio case. The behavior is the same on both.

Any advice is appreciated. Thanks.