If anyone steps across this post, its at least working for me using mosquitto_pub with the tenant ID added to the topic. The docs currently have:
“## Multi-Tenancy
Note that on multi-tenant environments such as Cloud, application IDs and other endpoints include the tenant ID, e.g app1@tenant1. On single tenant environments such as Open Source, the tenant ID can be removed, i.e app1.”
I can subscribe to uplinks using it as a username without adding the tenant id, but cant schedule any downlink, so just add it:
"v3/appname@ttn/devices/devicename/down/push"
works, while
"v3/appname/devices/devicename/down/push"
does not.
Edit: just to clarify; “appname” works as login user, im subscribed to “#”; and the uplink messages go to “…/appname@ttn/…”. In any case: its required to add it.