Lookup field not updating

I am using Airtable to track attendance, billing, and boat usage for a rowing club. I have an attendance column with a simple look-up field that connects to the billing table and shows if I have checked “Current Dues Paid” so I know that people attending practice have actually paid to attend practice. We recently invoiced for a new quarter, and I’ve been updating as people have paid their dues. However, the lookup field in the attendance table does not update. I have even unlinked it and set the link back up again, and it is refusing to show the last few I marked as paid in the attendance table. Is there something I am missing? I assumed these links would update as I updated information, but that is not happening in this case.