Hey, here’s some information about what’s going on:
Apparently, these random 520 errors are a problem of cloudflare itself. Since the last week, many users (myself included) have been posting here on the forum to talk about it, and coincidentally, all are happening under similar circumstances. And yes, it started early last week.
There are reports here on the forum that this issue is only happening with cloudflare free plans. A user has already reported that he tested some sites that were having problems, but within a pro plan, and the errors had simply disappeared. Another user recently posted here that when switching to pro, the problems were gone.
One of the moderators even commented in my thread I made about the 520 error (and other people’s as well) that due to the number of reports of the 520 error under similar circumstances, they would be escalating the issue to support.