XMLRPC errors started out of the blue

Starting around 12pm eastern today our free trial form stopped working and I started looking into it. Seems we started getting a bunch of XML RPC 404 errors despite nothing changing in our code.

We’re getting this error in our logs:
XML-RPC: xmlrpcmsg::parseResponseHeaders: HTTP error, got response: HTTP/2 404

At the same time as this is happening though, it looks like the API calls are working fine on another one of our sites. Any idea what’s going on with the other server? I’m assuming it’s some kind of configuration change that we need to make to get XMLRPC running properly but I’m completely lost here short of rebuilding that entire integration with oAuth, and can’t seem to find help anywhere.

I’m aware we should rebuild for oAuth, but right now we can’t get any membership signups until this random issue gets resolved so a bandaid would be much preferred.

Where/what is your free trial form? An IS order form? A landing page? If an LP then outside IS or using the LP builder? Is the 404 happening on the form itself or is it actually a confirmation/thank you page after the form?

It’s a custom coded landing page on our own site, not an IS order form.

We’re getting 404 responses from the XMLRPC api requests, not on the page itself. So for instance, after submitting step 1 of the form, we try querying the API to see if we already have this contact record or not. That call is just returning a 404.

I’m able to replicate the same errors with some small one off scripts on the same server. One, for instance, just pushes back the member’s next bill date by 30 days. All of the XMLRPC calls there return the same error 404.

I did just think to copy / paste those scripts to another server, and was able to successfully run the exact same code fine on the other server. Checked with phpinfo() and it looks like both servers are running the same XMLRPC version so I’m not sure what to make of this?

Going to create another ticket with our host to see if they have any input. As far as I can tell this narrows it down to either, IS is blocking our server or our server’s XMLRPC stuff is messed up?