Graphics.DrawMeshInstanced(); not rendering shadows at certain camera angles

Hi all,
Please see https://imgur.com/a/YKeKoq3 for example screenshots.

I am using Graphics.DrawMeshInstanced(); to render a forest scene successfully, but when flying through the scene shadows suddenly disapear and then pop back in depending on camera angle (possibly also camera posistion).
Has anyone seen this before or any idea what may be the cause?

I assume that Graphics.DrawMeshInstanced(); still uses project settings/quality/ shadow settings.

I create a Matrix4x4[] matrixList, and fill it with a Matrix4x4.TRS(translation, rotation, scale) for each tree.
then i call from Update()
Graphics.DrawMeshInstanced(mesh, 0, material, matrixList);

Using Unity 2018.2

 

6700 instances, using directx11

 

Sorry i should have been more clear, i am batching them into max groups of 1023

Start()
int count = forrestmapData.numberOfTrees;
matrix = new List<Matrix4x4[]>();
while (count>1023)
{
matrix.Add(new Matrix4x4[1023]);
count -= 1023;
}
matrix.Add(new Matrix4x4[count]);

Update()
foreach (Matrix4x4[] matrixList in matrix)
{
Graphics.DrawMeshInstanced(mesh, 0, material, matrixList);
}

What i have just found out, is that Graphics.DrawMeshInstanced() shadows are never rendered in builds of the game either.

 

HEy @Ardinius, did you solve this issue? I'm on 2020.1 and experience the same thing.