In the below image, A = 0 but the condition is not highlighted.

In this image, A = 1 but the condition is highlighted.

This bug only appears to happen under very specific circumstances.
- The output of the combinator must be connected to something.
- The output must be set to "Input count".
- The condition must be checking if A = 0.
Here is a blueprint that seems to always cause the bug. The decider combinator on the right is the problem one.
I am running Vanilla SA on the most recent steam update of the game.