Duplicate Location and x-nextjs-stale-time headers during Next.js redirects and ISR

Next.js applications using redirect or permanentRedirect alongside ISR or dynamic force-static features produce duplicate Location and x-nextjs-stale-time response headers on cache MISS or client-side navigation, leading to broken URLs containing commas and infinite redirection loops.

Read original evidence, the score breakdown, and historical snapshots in your workspace.