OS X/iOS Text Shortcuts Bug
There is a pesky bug that corrupts the synchronization of Text Shortcuts between iOS and OS X: deleted shortcuts keep reappearing and new or updated shortcuts keep disappearing. Don’t despair, there is an easy fix.
From the terminal window, run the command:
rm -rf ~/Library/Mobile\ Documents/com~apple~TextInput/Dictionaries
Restart your iOS device (it does not matter which one) and update your Text Shortcuts. The changes will be pushed to all your devices. Be advised: the command above will remove custom dictionaries from iCloud. If you ask me, it’s well worth it.