I'm still using SS 5 Pro.
I just got a new iPhone 14 Pro Max and all my observing lists and logs successfully showed up that were stored on iCloud from my iPhone 6 Plus.
When I create a new observing list and logs on my new iPhone 14 they show up on my iPhone 6, but when I create an observing list and logs on the iPhone 6 they do not show up on the iPhone 14.
Both devices have the iCloud backup selected to ON in "devices using iCloud".