Patch 4.20 game-breaking Rengar glitch

After losing a ranked game to this incredibly frustrating glitch I decided to make a post about it.

In my last game, when Rengar ults, the sign informing you he was near never appeared. He could literally walk around us and not have the "!" icon display.

This lead to fights where we literally had 0 opportunity to react, and eventually lead to a loss of the game.

Please investigate it, and fix it. Please.