If you and your partner both have published 10050 DM relays, then it will use NIP-17.  Otherwise it has to fallback to NIP-04.

If it doesn't post to the DM relays and doesn't say ok=true, then maybe something is up with the relays? I'll look at my logs after I post this to see if it is just a change in how we are logging.

If the relay requires AUTH first, it remembers what it is doing (logged as "corked") and after AUTH it retries the corked subscriptions.