I loaded up Minecraft 1.13 and went to do "/kill @e" but when I try, I make it up to "/kill @" and then the game still works, but I can't escape the chat box, move, type, ext. And upon the first try, the game went purple/pink but didn't do it upon any other try.
[EDIT] It works for some reason now... sorry for that!
Do you have any video/screenshot?