Incorrect error regarding authority to approve a requisition after check out shopping cart

Hi,

We have an issue that happens occassionly and we are not able to reproduce it at this moment. I hope the issue sounds similar to one of you, so you can help me further.

After creating a requisition, in the edit and submit screen the user get sometimes the error: "You do not have the authority to approve this requisition. Select the Manage Approvals button to add at least one approver before you proceed to the next step". (on the picture you can read it between the requisition lines and header approvals).

It happens with catalog, non-catalog and punch-out and it happens on rare occasion. When we save the cart and open the cart again, the error disappear and we can submit the requisition without any problems.