bugs in minecraft pocket edition 0.16.0 alpha build 4

my minecraft has some bugs , as I reach any port appears those bubbles doing as I was in the water and also I take damage , another bug is also the toggledownfall command I give this command the rain and then back also another bug is the xp his bar is full and every time I won a xp it increases as if full always , that's all I 've seen so far good I have helped,my phone is samsung galaxy gran prime !