[GAMEPLAY] Jarvan's ult is not working when he is stunned by ANNIE during casting ult

This game happens in TW server, 5.2 patch

When Jarvan ult, he should jump to the target, deal dmg and create terrain. However, if Jarvan is stunned by ANNIE during the jump, the ult will be canceled (just like when Ahri charms Jarvan). When this happens, Jarvan will jump to the target,dealing no dmg and create no terrain. I can see i did cast my ult because of the animation and the ability icon.

Also, after this happens, im unable to cast any spells, like Q, W, or even my summoner spells (both smite and flash), but i can control Jarvan to move and attack. After a few seconds, i can recast my spells.

However, the ult is not on CD, i can cast it to make another jump after i regain control of Jarvan. This is just like ---- Jarvan ult annie max range, then bug happens (no dmg no terrain, ult is available) . After a few seconds, Jarvan can ult again and jump on next target.

1. Ult champs
2. During casting, stunned by ANNIE
3. Jarvan did jump on his target, but dealing no dmg, creating no terrain
4. Ult's icon shows it is available even it has cast. Mana is used.
5. In the next few seconds, Jarvan is unable to cast any spells, including summoner spells, but Jarvan can move and attack (of course i have recovered from the stun)
6. After this, Jarvan can recast all available abilities

I have tried this at least 3 times in the game i just played. This happened every time when ANNIE stuns me.