BigTito

@ThorfinnI'm pretty sure you were right, thank you very much! I'm just not going to screw with the river mods because as pretty as they are, they all have done this and I do not like vanilla terrain.

@user 88 91 Sorry I forgot to post my results, I'm like 99% sure it was the "RiverGen" mod I had enabled. Been playing a new world and just went straight south for like an hour and nothing was out of the ordinary. I did leave "Plains and Valleys" on and so far haven't had an issue. @ArgentLuna Very weird, best of luck to you guys. I wish the worldgen wasn't so wonky because this game is one of the best out there.

@ThorfinnThat makes the most sense, I'll make a test world later with just Plains and Valleys on and see if at any point that weird stuff starts happening.

@ThorfinnIs there anyway I can fix the chunks in my world, or is my only option to just make a whole new world and test which of the mods it might be?

I have tried using commands like "/db prune 16 drop confirm" and "/wgen regen 5", but they didn't work as they just kind of regenerate anything the player messed with in the chunks. If it helps, it's happened across multiple worlds and my only terrain generation mods are "RiverGen" and "Plains and Valleys". Anyone have any ideas? Here's some pictures of it: