Unfortunately to my knowledge there’s no known fix, I can say you’re not the first person to experience this ,however this forum is moreso related to UEFN/Fortnite Creative related conversations/issues.
I’d recommend asking in Epic’s Player Support since they most likely have more resources for General Fortnite Connection issues
https://www.epicgames.com/help/
There’s also the following official fortnite communities where you could try posting for this issue
Reddit:
https://www.reddit.com/r/FortniteBR/
Epic Games Official Fortnite Community:
