Safari Reading List not syncing

I am a mobile app dev, so asking something as basic as this is a tad embarrassing, but I just don't seem to understand what I need to do to have my Reading List sync between my Apple devices. I have the sync over Wi-Fi setup on each device, have done this while cabled to my MacBook pro, done a sync, am powered, on the same Wifi, even prayed to the moon, but no syncing being done.

I have searched for a clear set of instructions, but with Apple changing the layout of Settings so often, all I have found are hopelessly out-of-date.

Pointers, tips, incantations are welcome! thanks.

On macOS, go to System Preferences → iCloud and check Safari.

On iOS, go to Settings → Apple ID → iCloud and turn on Safari.

I work in IT myself and had this problem just now on my 2017 MBPro 13". I would add to the Reading List on my iPhone X and they were not updating on the MBPro. I had all the items checked off as well. I went and turned OFF the Safari option on the MBPro, waited about 10 secs, then toggled it back on. It took about 30+ seconds or so and then FINALLY the list updated. I'm thinking the toggle Off & On finally triggered it to update. Hope this helps. I've read on other forums this has worked for some and not for others, thankfully it did for me. Now to see if it stays syncing. David