"ORPort ... Noadvertise" means your bridge silently doesn't work
If you set up a bridge with
bridgerelay 1 orport 9509 noadvertise
and then have somebody try to reach it with a client (usebridges 1 bridge x.y.z.a:9509).
The result is that the client will stop bootstrapping at
Jul 31 16:06:09.990 [notice] Bootstrapped 50%: Loading relay descriptors. Jul 31 16:06:10.752 [notice] no known bridge descriptors running yet; stalling
What's happening is the client is asking for /tor/server/authority.z, and on the bridge side, directory_handle_command_get() calls dirserv_get_routerdesc_fingerprints() which calls router_get_my_routerinfo() which returns NULL.
I assume that's because router_rebuild_descriptor() calls router_get_advertised_or_port() which calls get_first_advertised_port_by_type_af() which checks !cfg->no_advertise and ends up returning 0.