recently i noticed that sometimes mobs and guards will chase me for a long time. sometimes they wont stop chasing you unless you zone out or go somewhere they cant hit you (evade)
but if you are being chased by something, sprint off a short distance then keep spamming the hide key (H) and it sometimes will let you stealth which resets the mob
i dont know exactly how it works but i was testing it in noble tarantia, i was attacking players near the guards and when the guards chased me i ran around a corner and stealthed for just 1 second and they reset
hope this helps someone cos its really annoying when damn mobs chase you for a long time