Yes, it seems your Haven is running and available on localhost. So, then the question is, can your client (wherever it is running) access that localhost?
Ordinarily your client is not running on the same machine as your relay and so cannot access localhost, rather needs an IP address of some kind.
Yes, in a browser on my laptop (or phone): http://mytailscaleaddress:3355
hits the outbox end point from anywhere.
Also, Coracle and Damus show green light/connected when the relay is added (ws://mytailscaleaddress:3355) to those clients.
I've posted a note but Coracle shows connections: 0 to the relay.
May be beyond my pay grade, apologies, as I do not know Tailscale.
I might suggest viewing your Haven logs as you should see a log if notes are received, or trying wss rather than ws, or trying a reverse proxy.
GL
