I created an iron farm which uses end gateways and minecarts to transport myself in and out of the gateway to reload chunks for best possible rates and after about 5 minutes, I entered the end gateway to get back to the regular end island and fell through the world and died. I went back to the end and every chunk was rearranged, some duplicated or gone altogether. End gateways no longer work and every entity that was in the end at the time was removed as well as the contents of every storage block. The farm does not use any abnormal or unintended game mechanics besides the removal of bedrock to gain better access to go in and out of the end gateway. I was not using any mods or datapacks and was on a single-player world and the game wasn't lagging. The game did not crash at all and shows no reports, I have been playing for years and never seen something so odd happen, I have had instances when the game crashes but never when staying in the world.