(Singleplayer)

After entering a nether portal from the overworld, you can walk only in a few loaded chunks near the portal. When you would go to the chunk borders, the next chunk is empty. You could see mobs standing and glitchly spinning. Breaking blocks does nothing, drops are glitched as well, you can't pick them up. Blocks in empty chunks are not displaying whatsoever. If I want to fix this, I have to reload the world, leave it, and enter it. The same happent when going from the nether dimension to the overworld. I am not using any mods, only a texturepack.