Can't update client ownership to third party (even though only connection is domain-level)

Hello all, first post here. Really impressed with everything I’m seeing here. I’ve been going through the documentation to change my application to third party ownership and enable dynamic client registration. But I keep running into an issue when I try to update the application ownership.

When I try to patch my application/client, I get back:
Organizations are only available to first party clients

I only have one database authentication connection attached to this client and its is_domain_connection is true.

Any help for a new guy? Thank you!