It looks like this is triggered if, after meeting the night sister for the first time on Dathomir, you turn left to head down into the nightbrother village. You are supposed to instead use the ropes to swing across the gap. This path eventually takes you to the wandering stranger, the night sister ruin, then drops you down into the path to find the climbing claws. When you proceed through the story in this manner, the aforementioned slide works correctly.
I would still consider this a bug since you are not prevented from taking this path first by accident.
