Product Transport on an Unexpected Route

Hi everyone,
I’ve encountered an unexpected material transport behavior.

I expect the product to follow the transport links Input → Testing → Output.
The product does go through these process steps, but the actual transport path is not what I expect.

Specifically, the product is transported into the system from Node #13, but it is transported out through Node #40. However, there is no direct transport link between Node #13 and Node #40. It seems the product is choosing an incorrect path to reach the destination.

Has anyone experienced a similar issue or knows what might cause this behavior?
Any help would be greatly appreciated!