AR Receipt SLA rules not working

We are writing AR Receipt SLA program that will substitute the default receivables account with a custom 'hard-coded' constant code combination. We got the SLA to work, but our issue is that it is firing at all times instead when the condition is met.

Can you provide any help or guidance of what may be the issue?

Our logic is like this:

If Invoice transaction type = OMAHA then receivables account (when creating ar receipt) = constant value

If invoice transaction type = everything else, then the default GLdistribution account

The problem we are facing is the default GL distribution account is not generating.