Question Weird sprite sorting issue, animated gif in post to show what I mean

So I have this weird sprite sorting issue. It's a 2.5D game. What's weird is that it's almost correct but just misjudges by about 0.1 distance. The grass is rendering in front of the rock, even though the rock is physically in front of it.

Both have a sorting group. If I unparent the rock it works how it's supposed to. But it needs a parent so I can have it's pivot point at the bottom of the sprite.

You can see in the gif below what I mean.



Thanks!

 

Sorry, bumping this...