How to force Fortnite to use Easy Anti-Cheat instead of BattlEye?
I fixed the problem. To be honest, I don't even know if I was the one who fixed it. My Fortnite game needed updating, but I couldn't do it at the moment, so I enabled virtualization and started working (coding and making VMs sort of my hobby). The next day, I started the update. The game started normally. After I finished playing, I noticed that virtualization was still turned on! Fortnite started using EAC instead of BattlEye. This explains the fact that the EAC launcher came instead of the BattlEye launcher which I normally see.
So my conclusion is that if you turn on virtualization before updating or reinstalling Fortnite, it switches from EAC to BattlEye. Hope this helps :)