Mapping set in account rule not working in different priorities

Summary:

Mapping set in account rule not working in different priorities. We defined 3 mapping set and assigned to account rule in priorities but cost accounting not picking the correct account though defined in the mapping set.

Content (please ensure you mask any confidential information):

Segment Rule:

Priority 1- Mapping set 1 : To derive the COGS account for few order types.

Priority 2- Mapping Set 2 : To derive the COGS account based on Bill to Customer, so that the Orders other than the order type in mapping set 1 assigned to 1st priority will pick the COGS based on customer Bill to.

Priority 3- Mapping Set 3 : COGS for a cost element based on Bill to customer (Internal) and inventory org.