Some blocks you cannot destory in random area of the map, few skeletons do not de-spawn during morning they just stay stuck frozen during the day and shoot arrows at night while still frozen still. Tried making new words with random seeds and it still happens. Really effected most on;

Seed: 2088624149653386715
around ZYX: -193 / 64 / 270
Chunk 14 15 14 in -13 3 16
Looking at: -194 63 268