Lightroom Desktop: Pressing 'Enter' doesn't work!

When using the Crop tool, I'm told that pressing Enter or Return (I'm on a W10 machine with a Lightroom Desktop subscription) will accept the crop or straightening that has been done.

However, frustratingly, it does not. Pressing Enter simply reverts the photo back to its original state. I suepct it's a setting I need to change, because the problem happens in two instances.

Thank you