Requisition Account Builder is not respecting the Priorities of the rule

Summary: I have defined an accounting rule for one of the segments of the charge account.

Priority 1 is using Mapping Set A

Priority 2 is using mapping Set B

Priority 3 is setting a default.

When creating a RQ and clicking on the Save button, the priority 3 rule is used.

But there exists a mapping in the priority 2 mapping set B, but there is no mapping in mapping set A.

Expectation was to have the value from mapping set B and not the default value.

At which state will the account be derived? Because for other segments the rules are dependent on a DFF entered during the Review Cart phase.