connector 404

When trying to setup the Claude connector, using the third claude method of providing oauth info from google I get a 404 page in openseo (self-hosted) at the final step

First it takes me to a claude page that says "Finish connecting a connector?"

I click continue, it takes me to a url that looks like:

openseo.mydomain.com/authorize?oauthstringhere

yields "404 The page you are looking for does not exist."

if i used the detected/auto settings it yields:

"Couldn’t register with OpenSEO’s sign-in service. You can try again, or add an OAuth Client ID in the connector settings. If this persists, share this reference with support:...."