Why are notes not being saved when using Notes on my macbook pro?
Aside from making sure you've installed all the latest system software updates, try the following to "reset" Notes on your computer:


Quit the Notes application.
Turn off iCloud Notes sync on all your devices (on Mac, in System Preferences > iCloud, and on iOS, in Settings > iCloud).
In the Finder, pull down the Go menu, hold down Option to reveal "Library", and choose that.
Type com.apple.Notes into the search field and then choose the "Name matches" search option that appears.
Select the "Library" search scope.
The search should show a few folders with names like "com.apple.Notes", "com.apple.Notes.help", and "com.apple.Notes.savedState", and some files named "com.apple.Notes.plist" and "com.apple.Notes.help". Select all of those and drag them to the Trash.
Restart the computer.
Turn on iCloud Notes on just your computer.
Try creating an new note, then check against https://www.icloud.com/#notes to see if notes are being sync'ed successfully.
If that works, turn iCloud Notes sync back on again on all your devices.


Hope that helps!