This is a weird one. I bricked my current iPhone with a quick spin through the washing machine, so I dug out my old iPhone 4 to use in the interim before I get a replacement.
I deleted all the content and set it up as a new phone, and linked my iCloud account to it. It brought in all my notes, but they're old versions, including some notes that have been deleted.
My iPad, MBP and iMac are all syncing perfectly.
I turned off iCloud notes in settings and back on again, but the same (old) notes came back in again.
I created new notes on all devices:
"Note on iPhone"
"Note on iCloud.com"
"Note on MBP"
"Note on iMac"
"Note on iPad"
All devices but the iPhone synced with each other. The "Note on iPhone" didn't populate to anywhere else.
I am 100% convinced that I am using the correct Apple ID.
I decided to try using my husband's Apple ID, too. The exact same thing happened. The iPhone got old versions of his notes – eg, a particular note is dated Sept '15 on in phone, but May '16 on icloud.com and on his phone.
I checked that the date and time are set correctly.
Any other ideas?
Best Answer
Assuming your freshly-laundered phone was using iOS 9 & your iPhone 4 is still on the last available iOS for it, 7.1.2, then the reason it cannot sync to new Notes is because the new Notes feature was only introduced with iOS 9
Anything older will still be syncing to the older version, presumably last updated the day before you hit the button to upgrade to the new version when you loaded iOS 9 for the first time.