We have a flow with fork. One output of fork has a when condition with likelihood of 10%. Other connector is with else condition.
The problem we face after upgrade to Pega 7.1.8 is that the connector with low likelihood is not executing at all and always the when condition is triggered. So a particular flow which falls under 10% likelihood is being ignored which causes issues in the system.
We are facing the issue in a flow in couple of spots. But same flow has low likelihood connectors with when rule and likelihood of 10% which works fine. So the issue seems to repetitive but sporadic at few connectors in the same flow.
We never faced the issue with 6.1 but facing issues with Pega upgrade to 7.1.8
I would be surprise if the likelihood has anything to do with your issue. As far as I know the likelihood is just an indicator (the percentage of chance for your WHEN condition to be true). Now maybe the WHEN condition is always false for another reason. Have you tried to trace a scenario were the WHEN rule should be returning true ?