Ghasts just disappear with their fireballs

So I went to nether on survival and met few ghasts. 5 just disappeard on my eyes, even when I was in not more than 20 blocks away. Also one just fired fireball and teleported behind my back with it's fireball. It happend on few worlds so my Treecapitator datapack doesn't matter. Also I run fully Vanilla 1.14 without resource pack