Urgot Ultimate bug

Just played an aram as urgot. Ulted a player my ult went on cooldown, but the target could still cast, so they killed me while in my ult. I feel as though if I died before the ult took effect then it should not have gone on cooldown, if they didn't kill me before I ulted then they should have been suppressed and not able to cast.

Also ulted a yasuo this match while he was ulting someone else. It did no suppress him(though I didn't expect it to since he was already ulting) but since his ult ended before mine finished channeling the suppress, it did not trade places with us. My ult simply didn't do anything.