What can I do about it to get it back to standard?

When I go to Fortnite, certain things are always set, when I switch them over and close the game, they are as before. Thing is I have Directx12 in it even though I wanted 11. And if I want to change that, I always have to restart the game and then it's back to 12. What can I do?

Thanks in advance the one will be rewarded with a star.

For me I had to go to the game files, then right click and deactivate it as read-only. Then it was with me.

Ok, I'm trying to thank you