Elytra flying randomly drops the player down to the ground. I've found it happens most when descending but haven't been able to see if it's a specific angle/speed.
This is temporarily fixed. A proper fix will follow in the coming days. For now however, we have patched this up in a temporary way.
A proper fix is now in place. (Confirmation would be great). Will require testing. Please let us know if you continue to experience this @Videowiz92. Please include exact time stamps as well so we can track the problem in the logs. Fix is for all Magic Elytras, as well as the Star Rocket.
The temporary fix was something we are not willing to run long term. It has now been removed to implement a proper fix.