Contribution and Display Name

Hi, so we have a archiving project set up using the Contribution plugin; everything’s working great, except for the “Display Name” - in some cases, it seems users are assigned the Display Name they’ve likely entered in the “Your Name” field when contributing an item, but in other cases it seems to be generated from the email address they provided for their account. An example of both cases in our “Users” list
Anyone know why this would be happening? It ends up creating ugly, incorrectly-formatted citations. For example, this one in which the contributor has clearly entered his name (Benjamin Klunk) correctly, but in the citation his name appears as bklunk00,