Deleting keyboard shortcuts from your iPhone

Hey, this has probably been brought up before, apologise if that is the case!

Anyway...

I am a great fan of the keyboard shortcuts feature offered on nearly all Apple devices. The iPhone for example, instead of typing "What's up?" you can make a shortcut so that you only need to type "wup" in order for your phrase to automatically be replaced. I have set up hundreds of these ever since I got my first iPhone many years ago. However recently, my devices (iPhone 6+ and a few Macs) have started syncing my shortcuts with each other, which I think is awesome, apart from some shortcuts that are relevant when typing text messages and less relevant when typing professional documents on my Mac. This is however easy to fix by deleting some shortcuts and modifying them.

The problem...

I cannot delete nor modify my shortcuts, not on my Macs or on my iPhone. I understand that in order to delete a shortcut you must simply do the following:

On iPhone, go to: Settings > General > Keyboard > Shortcuts > Edit and then do what I desire.

On Mac, go to: System Preferences > Keyboard > Text and then you have the "Replace" and "With" columns where you can modify these shortcuts.

These techniques work for about 10 minutes.

Let me explain:

A long time ago I added the frivolous shortcut where "No." is replaced with "№", however this gets extremely annoying when my iPhone sometimes take the word "No" as being "No.", (you guessed right) and replaces it with "№". The word "No" is replaced by "№". I tried to simply fix this by going into the shortcuts settings and deleting it, then making a new shortcut where "Numr" is replaced by "№". Now I have about 5 shortcuts for "№".

I figured because my iPhone is synced with my other devices, the shortcut should be automatically deleted across all devices. This is however not the case, instead, my Mac sees that there is a missing shortcut on my iPhone and syncs it, adding the shortcut again because it is still saved on my Mac.

This is gotten way too far and it has become extremely annoying when you need to retype the word "No" 5 times each time you type it (including the writing of this forum post).

Typical iMessage conversation with me:

Friend: "Are you free tonight?"

Me: "№"

Me: "№*"

Me: "№****"

Me: "№ I mean!!**"

Me: "Negative, I am not free tonight"

Any help with fixing this is extremely appreciated!!!

Possible solutions that do not work:

1. All my devices are running the newest software version as of 21st April 2015, update does not offer solution.
2. Deleting the shortcut in all my Apple devices at the same time does not work, I have tried that, and deleting them off different devices in different combinations.
3. Modifying the shortcut does not work, I thought that simply modifying the shortcut would sync the modification, this was not the case, instead the modification was either deleted or made into a new shortcut.

Thanks in advance.