I'm having a terrible time with 18w47a as well. Plants don't grow, saplings don't grow, dirt blocks inserted into tree trunks, sticks, apples, and saplings spewing forth from the occasional tree, severe lag, trees leaves don't disintegrate/fall, it's a mess. The first world I created in 47a I spawned in what was apparently a bamboo forest, but the bamboo wasn't properly growing, it was single blocks of bamboo randomly planted in the air, on the ground, and spawning/breaking off like I was chopping them down but a lot like the trees spitting out saplings/sticks/apples. It was a mess. I have since created several worlds with random seeds and they all don't work properly in 47a. I gave up and switched back to 1.13.2 to continue playing my previous world.
I'm having a terrible time with 18w47a as well. Plants don't grow, saplings don't grow, dirt blocks inserted into tree trunks, sticks, apples, and saplings spewing forth from the occasional tree, severe lag, trees leaves don't disintegrate/fall, it's a mess. The first world I created in 47a I spawned in what was apparently a bamboo forest, but the bamboo wasn't properly growing, it was single blocks of bamboo randomly planted in the air, on the ground, and spawning/breaking off like I was chopping them down but a lot like the trees spitting out saplings/sticks/apples. It was a mess. I have since created several worlds with random seeds and they all don't work properly in 47a. I gave up and switched back to 1.13.2 to continue playing my previous world.