Slime mob not working

As the title says, my slime mob seems to not be working.

When in combat, it works just fine. Jumps at you, causes damage, keeps chasing you and all, but when outside of combat it just...stays there. If I run too far away or if I am in creative, they will not move a block. Everything I tried lead to the same result, but I want them to jump around when I'm not fighting them. I also can't use the slime AI since it causes problems