Hello Shift8 CDN Team,
Thanks for making this great WordPress plugin for CDN services.
Recently, I found that some of my sites will occur 502 Bad Gateway ERROR. Following your instructions on https://wordpress.org/support/topic/cdn-network-is-working/, I talked to my hosting provider. However, from their end, everything goes fine and works well! That’s very strange.
Then I did a lot of testing and found that the 502 Bad Gateway ERROR only occurs when the user is from Hong Kong. I’ve opened many Virtual Machines (VMs, just simply using Windows Server 2022 and browsing with Edge browser) from Microsoft Azure Cloud, Google Cloud, Amazon AWS Cloud, and Tencent Cloud, simulating user browsing from different places on the earth. For the VM located in the US, Japan, Mainland China, or others, everything worked! However, if the VM is located in Hong Kong, from whatever cloud service provider, it will occur 502 Bad Gateway Error (Just log in to WP-admin for Shift8 CDN Settings: Test URL before enabling : [Click to open test URL in new tab]).
I understand that you have CDN nodes in Hong Kong, but users browsing from Hong Kong will get 502 Bad Gateway errors. That’s so crazy.
I hope that this problem can be fixed soon.