i think this is a bug as my internet is good but it seems at random moments while playing killer or survivor on ps4 when i run it seems like i'm moving slower or jittering backwards. Just wondering if others have experienced this etc.
It's very likely your controller, even if you don't notice problems in other games I'd connect it to a computer and check it with a test tool to make sure that the left stick works fine (alternately, you could try running with the stick pushed down and see if you still slow down, as it's possibly only faulty in one direction). I once had the problem of randomly slowing down as well, and it turned out to be my DS4. This problem is usually reported by PS4 players, and the DS4 is known to develop problems with the sticks more often than other controllers.