[Vanilla 1.16.1, singleplayer survival]

This Bug occured in my world today, after loading a saved world. All Entities in a 3 chunk radius from the coordinates I saved at just stopped doing anything. They didnt move and I was also unable to push/damage them. I also tried spawning in new mobs in those chunks but they didn't do anything aswell. Out of those 3 chunks all Entities behaved normal. Reloading the world, restaring minecraft and even restarting my pc didnt help.