Kindred ult timer

When playing kindred in both 5's and 3's when you ult sometimes it does not go on cooldown. What i mean is you use your ult right before death and the UI says you didnt use your ult, but teammates can see your ult timer. If is fully light up in the UI and shows green on your screen, but i cant be used. I had to ask teammates when my ult was up.