iCloud not syncing to Macbook Air M1

I've followed the instructions, including turning iCloud off on my Macbook Air M1 and rebooting then turning iCloud back on, multiple times, yet photos that are automatically uploaded to iCloud from my iPhone 12 Pro Max are still not automatically downloading to the Macbook.

This is kind of a deal breaker because I bought the Macbook looking for a smooth, fast workflow for photos and video.

Also, I have three test photos in the Photos app on the Macbook, and Photos is stuck with a message: "3 Photos - Uploading 3 items." It's been days and the progress bar hasn't budged - clearly the upload and sync function isn't working.