The Extra Step Reveals an Unclear Transition
Looking at the sequence, you can see that you don't need a new figure: The challenge grows simply because there are fewer breaks. A Chassé can work on its own and still connect poorly to the previous weight change. The common extra adjustment step happens when you have already chosen the next direction but still don't know which foot can start it.
Determine the starting foot from the weight-bearing foot on 3, not just from the direction you want to move. If your weight is on the right, your left foot is free for a step to the left. If it's on the left, your right foot can start. Having your feet side by side doesn't automatically mean both are bearing weight. What matters is which leg you're actually standing on.
This way of thinking in terms of end positions also helps with connecting Rumba figures without resetting, even though their step sequence isn't used here. For your solo exercises, keep your focus on the transition: You won't practice turns or partner leading.
If extra arm movements make the side change uncertain again, practicing your arms and legs separately can help. Add the arms only once the foot sequence flows without an adjustment step. That way, you can tell whether the transition itself or the added coordination is causing difficulty.

