We need some advice on 503 Server Not Available issue.
We were seeing the 503 server not available quite a bit on our multisite solution. But usually after we reload the page is will be rendered fine.
Then we moved the DNS for our main site to Sucuri, we are keeping DNS of all our sub sites with Cloudflare.
After moving the DNS of our main site to Sucuri, we stop seeing 503 Server errors on the main site, but 503 errors remain on all the sub sites. As before, the error goes away when we reload the page, but this is really hurting the user experience.
We are wondering if the issue is because of the Cloudflare setting.
It’s impossible to say for sure; you’d need to thoroughly examine the logs on your server to determine the exact cause. 503 errors are almost always an issue with the origin server, not Cloudflare itself. When they are a Cloudflare issue, there’s a very distinct Nginx-like white error page that appears with almost no text on it.