[Gameplay] Nocturne ulti interaction with Veigar stun

I played a game as Nocturne and during a team fight the enemy Veigar zoned us by dropping his stun and I ulted to Veigar - to be clear, before I ulted Veigar was standing on the opposite end of the ring such that I would be passing through the ring twice yet I would not be positioned on top of the ring upon landing. I was still stunned upon landing, but I did not think I needed to use my spell block because I thought Nocturne was immune to CC during flight.

So I tested the scenario with a friend in a custom game in 2 scenarios: one where the enemy Veigar was standing on the opposite end of the ring as stated earlier and another scenario with Veigar standing in the middle of the ring. In both situations, Nocturne was still stunned upon landing after connecting with ult. I have not tested this bug with any other stuns in the game.

Despite the tooltip not explicitly stating Nocturne is immune to CC during flight (akin to Malphite's ult), I know from this example video Nocturne still auto attacks upon arrival despite the Amumu/Galio ult which leads me to believe there is a bug with Veigar's stun overriding Nocturne's immunity somehow. Am I wrong to assume Nocturne should be safe to ult through Veigar's stun or should I just know from now on to spell shield preemptively?