Two identical 'cluster' components behaving differently

I am using two cluster components that are defining the same logic, yet they output different results for the same input.
The attached .gh file should be self explanatory.
Any suggestions as to why it happens and how to avoid ‘accidents’ like that?

cluster input error example.gh (10.9 KB)

p.s.
The provided example is an extract from a more complicated cluster definition, so I don’t know how to replicate this result from scratch.