Guardian Angel doesnt come off cooldown

Im not entirely sure how to replicate it but after play a game of klepto Ezreal adc, ( maybe the stopwatch rune and after using then using to purchase a ) i died twice back to back, the first time used my GA the second time was within the cooldown so it was not usable yet. Around 15 minutes later when the game was about to end, i was killed under tower, my GA never came off of cooldown.