In using the Assigned To column, I found that several Contacts did not have their First and Last name fields populated. So, I went into My Smartsheet Contacts and updated all of my Contact items so that all have their First and Last name fields set. I then saved the sheet, closed it, reopened it and went back to the Assigned To column. I once again found the entries *without* their First and Last name fields populated! In evaluating the issue, it seemed to me that the Assigned To list was being populated from the list of persons I had shared the sheet with, not from My Smartsheet Contacts as I initially assumed. I am sharing the sheet via a group, so I went into Group Management and found the Contacts were missing their First and Last name values!
My question then is how to manage the Contact items in a Group? My assumption was that when I updated the Contact items in My Smartsheet Contacts, that the Group would have pulled from that to update those Contacts also. However, it appears that each Group is using a wholy separate list of Contact items stored independently from My Smartsheet Contacts. The only option I see is to remove each entry and readd them. However, that will span unwanted emails to those persons. How can I work around this?
Screenshot of My Smartsheet Contacts showing the fully populated Contact item:

