Update: 8/10/2019 I have figured out the cause - the river width was way too high. Lowering it so that it is only just clipping with the terrain fixed it. I have noticed in a map I am creating that the river water goes invisible when the camera is at certain angles. I am not sure why it happens and I cannot find anywhere that would cause it to happen. I have added images that show the issue: Here, half of the river cannot be seen, even though it is there (physics still works): When the camera moves a bit, it fixes:
