Dear Cosgrove,
Kindly confirm if the following options/questions are scoped/maintained which may have caused this issue
1. Do you want to define advanced approval limits for projects, shopping carts, purchase orders, and purchase order item approvals.
2. Then advanced approval value limits. The path via which this can be setup is Application & User Management -> Common Tasks -> Define Approval Value Limit.
3. If the Cost Center Manager does not have enough limit, then it checks along the CC hierarchy and finds the next CC manager who has the limit, and if no manager has the limit, then the highest CC manager(in this hierarchy) is set as the approver.
4. If the buyer responsible for a purchase order, and the approver of the purchase order are the same, then these users are filtered out from the list of approvers for the purchase order.
Regards
Leo