Answer

The issue was related to Cloudflare caching, not the Flutter service worker itself. Here's what was happening and how to fix it:

Root Cause

Even though the service worker version was updating correctly in the flutter_bootstrap_js, Cloudflare was serving cached versions of the assets, preventing the new version from being loaded immediately.

Solution

To resolve this issue, you need to:

1. Clear Cloudflare's cache:

   • Go to Cloudflare dashboard
   • Select your domain
   • Navigate to "Caching" > "Configuration"
   • Click "Purge Cache" > "Purge Everything"

2. (Optional) During development, you can:

   • Enable Development Mode in Cloudflare temporarily
   • Or create a Page Rule to bypass cache for specific URLs

Additional Notes

• The delay in seeing updates (next day) was due to Cloudflare's cache expiration
• Browser cache clearing alone won't help if CDN is caching the content
• This is not specific to Flutter's service worker but rather a CDN caching behavior

Hope this helps others who might face similar issues with Flutter web deployments behind Cloudflare!

Tags: cloudflare, flutter-web, caching, cdn