Why does checkout not allowing customers to finish checkout and needs last name, but is filled out?

Topic summary

A customer is experiencing a checkout issue where the system requires a last name field to be completed, even though it appears to already be filled out. This prevents the customer from completing their purchase. The issue suggests a potential bug in the checkout form validation or data processing that incorrectly flags the last name field as incomplete despite containing data.

Summarized with AI on November 14. AI used: claude-sonnet-4-5-20250929.

can’t checkout because last name is not working right?