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How to Fix Cloudflare 521 Error (Port 443 Blocked) - Volume Mount Causing Docker Container to Exit – Solutions-Docker Compose .env Not Loading: How to Fix

2026-07-28 12:07:43developer-tools
How to Fix Cloudflare 521 Error (Port 443 Blocked) - Volume Mount Causing Docker Container to Exit – Solutions-Docker Compose .env Not Loading: How to Fix

Final checklist

  • Confirm that the same symptom is gone after a restart or refresh.
  • Keep the smallest working change and undo temporary diagnostic settings.