Morgana's Ult Cancels Itself

I have been noticing this since yesterday, but I wasn't sure what was going on. I was playing against a Fiora and she would parry my ult and cancel it eve if I hit multiple people. Then I was playing against a Nocturne and whenever he feared me or if he spellshielded while my ult was already on him, it would cancel it entirely. Today I was playing against a Pantheon and he stunned me and cancelled my ult on everyone.

I am pretty sure Morgana's ult is not a channel and therefore can not be stopped or interrupted by Crowd Control. So I am not sure why this is happening, I asked the Panth what cancelled my ult just to see if he also saw my ult cancel and he replied "I stunned you" so I know its not just me seeing it cancel. This might just be a coincidence but Fiora has been in all the games I have noticed this, but she is not always the target of the ult.

http://leagueoflegends.wikia.com/wiki/Morgana this is where I am getting my information.

Steps to Repeat:

1. Pick Morgana
2. Ult several people
3. Have them CC her or try to Spellshield it
4. Repeat until it is cancelled
5. If it is Fiora and Nocturne and Pantheon specifically then pick them.