Following migration from DEV to LIVE, woocommerce can’t checkout

I had already changed the config and options file to have the correct
site root, logins, etc

Did you change all URLs in the database, or just the two site address options in wp_options?

If there are old MAMP URLs in the database, this could be the issue. See WordPress Serialized PHP Search Replace Tool to correctly change URLs in the database. Don’t change URLs in a text dump; this will break serialized data.