Unable to Change Measurement Units Photoshop 'New Document' Window [SOLVED 26.6 m.3011]

I'm experiencing an issue with Photoshop's "New Document" window. When creating a new document, I'm unable to select or change the measurement units (e.g., from Pixels to Millimeters or Inches) or modify the color mode (such as RGB to CMYK). Both dropdown menus appear clickable, but no other options can be selected—they remain stuck on their default values.

I've tried restarting Photoshop, but the issue persists.

Could anyone help me understand why this is happening or how I can fix it?

I'm using Adobe Photoshop (26.5.0 release Beta).

Thanks in advance for your help!