Factorio Forums

Basically, the signal won't translate to the output signal unless it is set to output '1'

If I change the accumulator's output signal to green, then this setup works.

This was changed in version 0.13, decider combinators no longer 'change' the signal type unless you output a specified signal with value 1. The rest of the time they will output the desired signal at the input count based off of what is on the input side.

Here's the official patch note:

Decider combinator "input count" option makes the combinator copy the count of the specified output signal from the input signals, instead of copying the count from the condition. This might break some setups. 13706