[GAMEPLAY] Karthus Ult cancels guardian Angel in TFT

In my last TFT game a player who I had beat multiple times in a row some how came back and beat me to win the game. The only difference to the previous matches was he added Karthus to his comp. As I watched the games I realized my three guardian angels were not reviving the champion if Karthus ult was what ended up killing them. I found this issue to be reproduced in all further games i played with me using guardian angels and my friend playing with me having a Karthus on his lineup. Just wondering if anyone else has experienced this issue.

tldr: Karthus ult cancels guardian angel revive.