There's a mountain building itself 1 block at a time in the middle of a lake. It's similar to the way that when I blow something up with TNT, it regenerates all the blocks after a few seconds. Except I didn't blow anything up this time, it's just happening by itself. I've heard this is a towny related thing, but I can't find the right fix for it. This is on a spigot server running 1.14.