409 Errors with CF 7 and CDN?

Making a new post to cover this issue as my old one wasn’t specific and I’ve since been able to more accurately narrow down the problem.

For reasons I don’t understand, our contact form fails when being used with Quic.cloud CDN, but only on certain nodes.

However, since it seems difficult to obtain detailed logging, I can’t quite figure out why this is failing. Furthermore, the CDN provider is having a hard time figuring out the issue as well since 409 errors are somewhat rare.

The issue is easy to replicate today and is tied to only certain regions of the world. Prior posts on this matter point to issues with Mod Security at the hosting side, but since this only affects certain CDN nodes and the issue is resolved by disabling the CDN, I’m not sure we can do much on the hosting side to correct this issue.

In our case, as of today, the contact form works perfectly fine when accessed from New Zealand, the UK and the United States (all of which go through different IP addressed CDN nodes in the Quic CDN). However, when we try to access it via the CDN node that covers Switzerland, we get the 409 errors as shown?

https://imgur.com/ertNYhd

Switching locations (via VPN) to the UK or New Zealand and doing a page refresh of the contact form resolves the issue until we return to the Switzerland CDN – c304977.tier1.quicns.com

• This topic was modified 1 year, 2 months ago by skydivider.

The page I need help with: [log in to see the link]