How to fix a deployed app that works on Wi-Fi but not on a mobile network?

RuchiDeo — Sat, 04 Apr 2026 17:10:58 +0000

My friend, you’re trying to fix an app deployment that works perfectly on Wi-Fi but fails to load over mobile data. You’ve checked every configuration but have no idea where the leak is. I have the solution to your problem.

The culprit: DNS blocking by your ISP (Internet Service Provider).

Before jumping into the fix, keep two things in mind:

You need a custom domain.

If you’re using a free hosting service, this issue is incredibly common (especially for us developers in India!).

What’s the solution?
Use Cloudflare.

How does it solve the problem?
It’s simple. Cloudflare adds a proxy layer that acts as a middleman between your domain and where you’ve hosted your frontend and backend. Instead of the ISP blocking the hosting provider's "flagged" IP, they only see Cloudflare’s "clean" IP.

The Steps:
Point your domain to Cloudflare: Change the Nameservers in your original domain registrar (like GoDaddy or Namecheap) to the ones provided by Cloudflare.

Configure your Hosting Platforms: Go to the settings of both your frontend and backend providers.

Add a Custom Domain: Select the "Add Custom Domain" option. The provider will give you specific DNS settings (like CNAME or A records).

Update Cloudflare Records: Go to the DNS tab in your Cloudflare dashboard. Click Add Record and enter the credentials provided by your host.

Submit and Wait: Once you save, you’re done! Give it some time for the changes to reflect globally (DNS propagation).

If you need more details on this topic and hear my struggle story, visit RantDoc: How to Fix DNS Blocks and “ISP Only” Access with Cloudflare

That's it for now.

See ya!!

DEV Community: RuchiDeo

How to fix a deployed app that works on Wi-Fi but not on a mobile network?