Fill Command no longer Works

I was playing the latest version of Minecraft, but I tried using a fill command and it did nothing. My friends tried too, and we all got the same error message. "Cannot place blocks outside of world." But that was impossible. I flew there in creative mode, and I saw no world border. We tried everything, from keeping both chunks loaded, to rewriting the command. Please help with this! It has happened 2 times, and it’s super annoying.