Hi @Brian Swichkow35
Our Zapier integration, as far as I know, never worked with custom fields properly. I believe Product was looking into this at one point, but it isn’t working properly with custom fields, and there’s no ETA on when Product will circle back to ensure it works properly. There's already a request for this.
If you have further questions, I recommend you email help@convertkit.com17 to take a look at your account.
Thank you!