My website is using digitalocean as server and connect to Cloudflare.
When I am using the website, no matter from front end or back end, if I click to other page, the 521 error may occurs sometime. Sometimes, I just need to wait for few seconds and the page will automatically refresh and back to normal. Sometimes, I have to refresh the page manually and it will back to normal. The 521 error doesnt occur all the time, it occurs occasionally.
After I disable the Cloudflare, the 521 error disappear. However, if I enable the Cloudflare, the problem comes back.
Thank you for replying to me. I am not sure if I checked the correct post, could you send the link to me so that I can check if I tried it before? Thank you