When playing on certain worlds, if i go past a certain point in the world ( which i assume the problem is loading new chunks) the world freezes, which means i get stuck in fly mode, cannot interact with any blocks or mobs, all the mobs freeze, and i cannot use items. 
Its possible its purely to do with my computer, but this only started happening after i updated said worlds to the newest 1.16 snapshot.
The images may not be very clear, so i tried to show whats happening to mobs and my player.