This may happen in other zones but the one that I always have issues with is the Lake area in the monoliths.
Using Shuriken in the water will only throw the shuriken a foot or so right in front of the character and not its full distance. I’ve tested to see if its just visual but it is not, if there is an enemy in front of you they wont take damage unless they are standing right next to you.
However, if you walk onto one of the sand dunes. the shurikens work properly and will go their full distance, you can however see that they do follow the slope of the terrain.
The shurikens that your shadows/clones create though, work without issue.
I am using the passive that makes 1 large shuriken instead of the multiple fanned out shurikens, I have not tested the base form of the skill.
Also I am unsure if this applies to other projectiles that shoot out from your character or are thrown.