About Changing Assigned Approval Sequences
You can change the approval sequence assignments for reviewers in the Reviewers tab of the unapproved invoice line (in the AP Unapproved Invoices form).
If the reviewer in question is in the header Reviewers tab, you can change it there to affect all lines at once.
If you change approval sequence numbers for reviewers in HQ Reviewer Group, only newly created invoices/lines will be affected; changes to approval sequence numbers do not update for existing invoice lines unless you remove the group from the line/header, save the record, then re-add the group. While this updates the new approval sequence assignments on the Reviewer tabs, it also removes any existing reviewer approvals and will require those approvals once again.