Matrix multiplication calculation error during Niagara System Update Stage

When I was studying the PBD system in Content Examples(Niagara_Advance), there are some custom code got my attention, I replicated the code in my own project, here is the bug(?) I found.
The Custom Hlsl block returns an identity matrix, and is connected to the RLocal input of Custom Hlsl 002 block.
my first thought is to remove this useless multiplication(since M * I), like 001 block under. However, I got different result.

I tried to use Mul(Matrix * Matrix) node with multiple input node, I got the same wrong result.
Then I tried to use multiple Mul nodes with two inputs each chained together, I got the correct result this time.
Liked the MatNodeNoLocalR in the picture ( The green arrow is pointed to the wrong output, it should be MatNoLocalR )

I suspect that there is some issue within the VM? I have no idea how System Update Stage works. Can I get some direction about the cpp files about this problem?

在研究Content Examples的Niagara_Advance中PBD时候,发现使用custom hlsl或者 mul matrix*matrix节点进行多矩阵连乘时,会出现计算结果错误的情况,我用自己的工程复现了System Update中 初始化NeighbourGrid模块中的这部分代码,如图

我尝试使用了 自带的Mul节点,进行多个input输入,结果也是错的。


由于不太明白System Update的更新机制(似乎是用虚拟机进行计算?),不知道这是不是一个VM的Bug。。想了解下如何解决这个问题,或者有没有大佬可以科普下 Niagara System Update的C++代码在哪个位置,想深入了解下Niagara的更新机制。。 谢谢~

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