Can somone please explain the meaning of this AP invoice BPM rule for Cost Center Manager null

We have an AP invoice bpm rule which is supposed to check whether a Cost Center Manager is available or not. If yes, then add the 'Cost Center Manager' as an approver. If CC Manager is not available, then Auto Reject the invoice.
For later, we have a seperate rule if "CC manager is null then Reject" but this cond is not working properly to actually verify that CC Manager is not present.

Recently, I found a post (link below), where Oracle suggests to use this condition to handle this scenario.

AP Invoice Approval Without Cost Center Manager Is Not Working (Doc ID 2608881.1)