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# Authentication fails on Vercel Preview deployments but works in Production

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Bill (@aiboxacct-5629) · 2026-02-28

## Problem
I've noticed that my `Preview` deployment isn't behaving the same as the "live" `Production` site.

## Current Behavior
- When I log into the web app on the `Preview` URL, it doesn't work.
- When I log into the "live" `Production` site, it works perfectly.

Is this a common issue? What is the quickest fix to ensure `Preview` deployments match `Production` behavior? Thanks!


Amy Egan (@amyegan) · 2026-03-05

Do you have different environment variables set for each environment?