I forgot to take a picture and i haven't tried to recreate the scenario yet, but here's what happened.
me and my friends were playing a game when an enemy became really toxic in the all chat so we decided to mute him... here is where the bug begins...
the chat disappeared the second i pressed the mute button. after that i tried to unmute him to fix it... it helped somewhat... the chat looked like this _for the rest of the game the chat was like this for me and my friends every single one in our team got this after pressing the mute button (the enemy champion was yasuo). when this bug occurred we decided to test it a little after pressing the mute button a couple of times i had no more chat! even when i pressed Z (Z shows the entire chat log), the chat was gone. i couldnt even read my own messages. after pressing it a couple more times the recent chat returned but i still couldn't see the chat using 'Z'. after pressing it a couple more times again it disappeared again._
so i hope this gets fixed soon. it is kinda annoying to read the chat in italic the whole game or even being unable to read the chat just for muting a toxic person.