Mbuna will often circle chase,which at first may seem like spawning dancing. It's not.
The difference if I can describe is, Circle chasing is fast and furious,and looks like a race.
Spawn dancing is only fast when the male shimmies in front of the female. You will notice the male will shimmy,swim away,and expect the female to follow him. Sometimes she won't because she may not be sure he is just dancing,she may think he's being a brute,and she will swim away from him. But after his guaranteed persistence,she will eventually follow him to a male chosen space in the tank where they will begin to dance.
This circling looks more like they are taking turns nudging each others tail sides,and will be less fast and furious then the circle chasing you most commonly see.
If you want to give yourself the best chance to see a male spawn with her,keep a close lookout for where the dominant male has made his cave. You will see him digging out substrate from this area,and he will guard with all his might.When it comes time to do the dance that cave is where he plans to make the magic happen