Persisting connection drops between Madrid (MAD) and Amsterdam (AMS)

@bwalters if it helps, this is what I noticed:

Some websites experience issues loading static files from the origin. On the browser side, these resources appear stalled in Cloudflare’s cache and eventually time out after 19.2 seconds, returning a 522 error.

Observations:

• Once a static file stalls, it remains stalled until the cache is cleared.

• Clearing the cache temporarily resolves the issue, but after a few hours, another random static file starts returning a 522 error.

• Adding a query string to the static file (modifying the URL slightly) makes it work again, and the origin becomes reachable.

• The issue occurs only when the Cloudflare node is Madrid and the origins are in London or Ireland. Origins in Paris work fine.

• No issues occur with any other Cloudflare node.

• The problem persists on both Pro and Free accounts.

• Extensive testing using VPNs and checking the node with RayID confirms this behavior in our case.

• Switching from IPv4 to IPv6 resolved the issue permanently in our case. But I have tens of potentially affected sites where ipv6 is not an option.

Would appreciate any insights or guidance on resolving this issue.