Error Web server is returning an unknown error

I am using Woocommerce and have been using Cloudflare for the past 1 year.

I recently reinstalled woocommerce and upgraded my website. soon enough I started getting this error [520]
I have tried everything from disabling cache to resetting it. The error ONLY Comes in the admin panel https://decomart.pk/wp-admin my website is accessing fine https://decomart.pk/.

This error is VERY VERY FREQUENT now and I am unable to work. Please help.

Check that the origin server is not restricting access to /wp-admin and preventing Cloudflare’s IP addresses from connecting to it.

[add] Your domain isn’t currently using Cloudflare anyway…
https://cf.sjr.org.uk/tools/check?44b77434b8704228ac436e8392354249#whois

Hello,

Sorry to hear you are having issues with 520’s. These errors typically originate from the origin server as SJR mentioned. When you see the Cloudflare 520 page when you were using our nameservers did you see it at the host end? If so this would be an issue with your instance either denying connections from us or resetting them when we are communication with your origin. Below is a document that details items to check to see why a 520 may be issued. I would check your access logs to see why these attempts to this admin page is failing. Which will help you remediate the issue.

It could be a few things, but I would agree to make sure your origin is not denying connections from our IP’s as a first step.

If the Cloudflare error page states the error is on Cloudflare when you test this again please create a ticket and drop the ticket # in this thread please.