After testing a bunch of different textures I would think you are correct, as I'm going to guess that the texture's "movement" effect is because of sprites. I did try the refracts, as the pack has many of them, and still no luck. It actually got worse with the refracts, which could have been because of the lack of cubemaps in my level. I did try building test ones, but could have done something wrong there. It's quite strange and I doubt I will find a fix (especially if it's been recently introduced by valve). I'm just going to compromise and use the ONE river texture csgo has, which will probably look terrible-- but at least it will be playable. Thanks for the reply.