My Website Server Is Down When I Use Cloudflare

My Website is Running On Namecheap I Use Cloudflare SSL For My Website. But It Shows Web Server Is Down When I Turn On But When I Turn Off Cloudflare Website Is Working Properly. It Means There Is No Problem With Server Side. I Even Checked With Server Providers. They Said To Contact Cloudflare.
Without Cloudflare:
It’s Working I Can’t Post Images Due To New Users Restrictions.
With Cloudflare:

Please Resolve My Problem.

Hi @praveenkumarappu7,

A 521 error happens when Cloudflare is unable to make a TCP connection to your origin server. Review the suggestions in this Community Tip for Quick Fix Ideas.

I Checked Everything And It Seems Everything Is Good. But Still The Error Shows.

Have you done number 4 in that article and got your host to whitelist the Cloudflare IPs?

Yea they said they are not blocking the IP and They Allowed

If you have tried everything in the linked article, contact support with a RayID of a 521 and they should be able to track down what went wrong.

To contact Cloudflare Customer Support, login & go to https://dash.cloudflare.com/?account=support and select get more help. Please give Support the complete details and link to your Community post. Here’s a bit of background on Cloudflare Support for reference:

Hi @praveenkumarappu7, after you’ve disabled railgun, let us know if you continue to see the issue.