The guy from spigot forums here,
Had a look at your server, noticed a couple of things.
Your fall damage problem isn't fall damage problem. I think it might be your TP protection that made you think so.
It works for me.
Then there's /rtp, internal error on every rtp, spams your console. This is due to the plugin being made for 1.8, the sounds have changed in 1.9 or 1.10 not sure. Either update your sounds in the plugin (it's on the page of the plugin but that's way to much work if you ask me), or I'd like to advice this plugin: https://www.spigotmc.org/resources/fubs-random-teleport.1094/
Also, /help is not accessible in your survival world, and there are no perms for /ehelp either.
Goodluck with your server,