This is a very disastrous bug that has been going on for years now. If you log into a world, spend only a few seconds on it, and then log back out chunk errors happen. A LOT of them. These errors grief your base and mess up the terrain. Mojang, this is VERY important to fix. I lost about 5 worlds like this. For the versions, it's been pretty much from the moment I've started playing Minecraft (1.13). The world I've provided in the screenshots is my most successful one and I don't want to lose it. For platforms, this bug is on every platform. What I want you Mojang to do in the next version is to fix chunk errors in singleplayer worlds.