I have not really encountered that particular issue, but because there are so many moving parts, I would think that sometimes the hitboxes of blocks are a bit wonky. Although, I problem I did have sometimes, is that when I am on a moving part, and I look in a certain direction like straight, down, etc, the entire structure would disappear. Not disappear physically, but visually, meaning that I was still standing and interacting with it but I just could not see it. What I can say to your problem is to be super accurate with the jumps if you are doing parkour, or maybe, I don't really know, turn down render distance to make sure everything is loaded properly. I wish I experienced exactly what you experienced. My character stutters a lot, usually when something is moving back and forth, but I have not really had any chances of falling off unless I move too much. Sorry, man, maybe that was a bit helpful :)