Artboard size (weird) and how to rotate a single artboard?

@J453Yes, that was the issue. Thank you so much for the tip 🙂

Curious. I can't repro. If you tickle the panel - making its size slightly larger, does those edit fields light up?

Thank you @J453 for the workaround. That's a good option.

I didn't know that artboards were kind of cut-outs of the larger image. Good to know.

Just a quick question: any specific reason why the artboard information only shows me the Width and the X position?

Artboards in Photoshop all share a single document - which is the size you see in Image Size - and each artboard is a kind of cut-out of the larger image size.

Workaround:

You can rotate the view/aspect of an individual artboards by 90 degrees using the Aspect Ratio buttons on the Artboard tool's Options bar: 

You can use the transform tool to rotate the layers/content in the artboard around the center point: