Game stops suddenly

Sometimes, when I just go around or something, the game stops working. When I break a block, nothing drops. When I break the bottom of an bamboo, the stems above just fly around. When I land with my elytra, i stay in the position of the flight, and if I activatet a rocket while this startet, I fly around constantly with the speed like I fire fireworks every second. When I go save and quit to title, i would save the world forever unless i stop it with the Task Manager.