why is it when i lock on my character moves back so slow

[Alsar]

it's because you're locked on. Meaning you will always face the target. And if you try it in RL running backwards at full speed doesn't really work.

[Niwashi]

And if you try it in RL running backwards at full speed doesn't really work.

In RL, you may not be able to run at quite the same speed backwards as you can forwards, but you can certainly run backwards, and it's a lot faster than walking, let alone this slow creeping pace that being locked on forces on us in game.