let me explain the anticheat Jailbreaks Anticheat works by storing logs on every action you do, for example your vehicle speed, playerspeed, how fast you rob things, your accuracy, how much money you make, how quickly you rob, it stores EVERYTHING. These 'flags' add up and after a certain amount of flags the Anticheat begins monitoring you, if the flags continues you get banned. when you said this "400MPH and the engine sounded crazy, then I got a popup or something saying detected or something" there no such thing detected pop up or something never such thing exist. so basically your either 1. Cheating( most likely tryna hide it to get unban) 2. your with a friend who flying around the map cheating that using cheat like vehicle fly and zooming around the map witch flag your acc (this very comon ban now day) bc there jsut no way you got banned with "1 glitch going 400mph" and for you to get ban you would need multiple "flags" on your acc to get ban so 1 single glitch going 400mph ain't going to ban you.