Big fruad by EA while playing UT 25

Sounds more like you went up against a hacker. I come across them every other weekend in Champs, its the same thing and I notice it straight away. The commonly used hack slows your players to a crawl, no sprinting, depending on what else they have turned on, they can also drastically reduce the passing stats of your players along with whatever else really. Most of the time it's just the sprint speed to reduce the risk of the anit-cheat kicking in, though the game you crashed on it sounds like it did actually detect it and kick in hence the crash. It's a pretty massive issue across the PC player base, EA don't seem to care enough to do anything about it which is insane. Best bet is to turn crossplay off if you have it on, assuming that is that you're playing on console, if you're a PC player however there's not much you can do about it unfortunately. People cheat, f*** knows why, how desperate do you have to be to win a game.