IB requiring serial number for ATO Model when updating Install Location

Converted ATO model/ ATO configuration records to Install base during production cutover.  Since ATO model is serialized but there is no serial number entered while configured * item gets the actual serial number.

All data came over as expected for different models.  But now one model is behaving differently then others. Everytime we try to update it at the top parent level (ATO model level), we get this error:

Instance Cannot be marked as Creation Complete, because one or all of the following mandatory parameters are not available: Serial Number (If Serialized), Lot Number (If Lot Controlled), Revision (If Rev Controlled), Instance Location, Instance Status.