Yesterday I found a friend in fortnite. He was also quite normal in my friends list. I then went to sleep after a while and today he is no longer in my friends list and if I want to send him a friend request, it says that he could not be found has been
He must have deleted you and blocked you. That's what it sounds like…
If you play on the Ps4 then it will be like that, with pc I don't know exactly
Play on switch
He probably blocked you anyway