Random 520 error for a good with no firewall since TODAY

[user5056]

What is the name of the domain?

festivalnet.com

What is the error number?

520

What is the error message?

Web server is returning an unknown error

What is the issue you’re encountering

Random 520 errors with no firewall since TODAY

What steps have you taken to resolve the issue?

Tried to disable firewall, access directly (good) and through cloudflare (bad), tried to disable HTTP/2 to Origin and HTTP/3 in cf settings

What feature, service or problem is this related to?

I don’t know

What are the steps to reproduce the issue?

access website
Cloudflare Ray ID: 89ca81500ddd0975
NO it’s not website issue. It was working fine until today and still responds instantly when accessed directly without cloudflare. I did tried to disable firewall and my hosting provider can’t find anything either. The server isn’t loaded at all and nothing wrong is in the logs.
Since today though the access through cloudflare is sluggish at times and every few hits it times out.
I would probably just disable cf but we have ezoic ads configured through it.

Screenshot of the error

[user5056]

https://festivalnet.com/cdn-cgi/trace
fl=363f49
h=festivalnet.com
ip=47.199.130.135
ts=1719881778.517
visit_scheme=https
uag=Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36
colo=MIA
sliver=010-tier1
http=http/2
loc=US
tls=TLSv1.3
sni=plaintext
warp=off
gateway=off
rbi=off
kex=X25519Kyber768Draft00

[hollynghiem]

Can you try to turn of HTTP/2 to Origin?

Make sure Cloudflare IPs are allowlisted at your origin.

And try some suggestions at Troubleshooting Cloudflare 5XX errors · Cloudflare Support docs.