SES Revocation causing M7021

Good day,

I am receiving an error when trying to revoke an SES.  The user created an PO with a quantity of 1 PU and a value of 1840.  When they posted the SES it was posted with a quantity of 1840 and a value of 1.  They are not trying to revoke the SES and it is erring with M7021 - Deficit of PU GR quantity 1839 PU.  No IR has taken place.

Any ideas on this.

Thank you for your help.