Sometimes the environment variables that you use locally can get out of sync with what you have deployed to Netlify.
Can you describe how you are setting your environment variables (not share the keys, but describe how you are setting them)? You can check the environment variable that you netlify project is using with the command netlify env::ls. Here for an article about managing your environment with Netlify.
Also, did you use the Fauna Netlify Addon to create the database? If so, make sure you complete the process of moving the database to your dashboard with netlify addons:auth fauna.
UPDATE:
Ha! you beat me to it, and I hadn’t refreshed my page . Glad you got it resolved!