first time downloading this for a server, and you climb everything, and move / jump slow? also when you jump off things you float down slowly but still take damage? how can i fix this im on 1.16.3

I don't remember what the fix for this was, as someone reported it a few months ago and then got it working, but it's something with your server, not a BOP issue specifically. Either a mod conflict, you using the wrong version, or something else. But you're pretty much on your own with it.