Next.js ChunkLoadError Only for US Users App Works Fine in India

Stack

• Next.js 14.2.2
• EC2 (Mumbai, ap-south-1)
• Nginx reverse proxy
• Cloudflare CDN (recently added, but issue existed even before)

The Issue

After deploying to production, our Next.js app works perfectly in India, but US users (New York, Virginia/Boydton) are getting ChunkLoadError on almost every page load.

Example error:

ChunkLoadError: Loading chunk 704 failed.
GET https://xxxx.xxx/_next/static/chunks/704-xxx.js
Status: 404 (HTML response instead of JS)

Sometimes the endpoint even returns:

• 200 OK with 0 bytes
• Or a 404 even though the file exists on the server

Framer pages on the same domain load fine everywhere. Only the Next.js chunks are failing.

What I've already tried:

1. Nginx buffering changes

   Added buffer settings to fix any truncation issue. No effect.

2. Full rebuild + restart

    rm -rf .next && npm run build && restart
   

   Works temporarily, then fails again for US users.

3. Verified files on the server

   The chunk files exist in .next/static/chunks/.

4. Direct access to Node server

   Fetching the same chunk from localhost:3000 works fine.

5. Added Cloudflare CDN

   Moved DNS to Cloudflare expecting caching to fix the issue - but the same problem is still happening.

Symptoms

• Indian users → no issues
• US users → consistent chunk failures
• 404 responses returning HTML instead of JS
• Sometimes 0-byte responses
• No firewall rules blocking traffic
• Route53 simple routing
• Only one EC2 instance (no race condition from multiple servers)

What I'm trying to understand

• Why do chunk files return 404/empty responses only for certain regions?

• If the files exist and Next.js serves them locally, why does Nginx return HTML/0-bytes?

• Is this a caching or buffering issue with Nginx/Next.js?

• Could Cloudflare be interfering even with "cache disabled"?

• Is this related to Next.js static chunk invalidation?

What I need help with:

• Has anyone seen region-specific ChunkLoadError with Next.js?

• Is there something obvious I'm missing in the Nginx → Node setup?

• Could this still be a deployment race condition even with one server?

• Is there a reliable fix without moving fully to a CDN?

• Any suggestions for how to debug Nginx returning HTML instead of JS?