It could be dependent on other things or versions, playtime, detection times, etc.I literally just loaded it right now and nothing happened, yes I have v4 installed yes its latest so there is only 2 possible reasons why this is happening.
1. You are cheating
2. You installed something else or have a virus on your pc that is modifying something you don't know about
1. I am not, and nor are the others who have had this happen to them.
2. I reset recently and only have installed programs from signed and trusted developers, and then again why would a virus be modifying or injecting code into the Fortnite process...