3 Domains on same server, 2 having constant "Site is offline" errors

Hi,

I have 3 sites running off of the same folder on a server, all run through cloudflare.

2 of the 3 are constantly getting a “Retry for a live version” and sometimes an unknown error 520 while the other one works perfectly fine. They are all on the same server so I can’t understand why 2 of the 3 would be having issues unless it’s something on cloudflares side.

Has anyone else run into something like this lately?

Thanks