Nostalrius Begins - Quality wow vanilla realm (1.12)

Marks.. When I mark people or NPC, whether I'm the leader in pvp or the tank in a dungeon or helping somebody out, the marks will either clear themselves after an enemy dies within the vicinity, or they will just randomly dissapear. It would be ideal (I know it's not blizzlike) if the marks could work until the target is dead, rather than just clearing at any given time.

Is this a possible change?

This only happens in 5 mans. Yes, it's annoying as fuck.