Tried restarting the launcher to no avail.

My friend and I keep falling through the map at random points throughout the map. Also, the character will randomly stop following the mouse and start walking to the bottom left of the screen. Kills us and loses lives when we fall through the map which is really frustrating. When scrolling over potions or arrows, it doesn't show their name and doesn't highlight them (as if they aren't there).

Internet speed is great and regular Minecraft worked fine.