You have to enable Location Services/GPS on your Mobile phone and then open WatchPower App, also verify if you have given Location access permissions to WatchPower app
Happened to me as well,
Once you click connect inside Watchpower, then instantly you will see a Connect & Peer option on the status bar of the phone, Click CONNECT & PEER twice, then you might see password box.
With me the password box did show up doing the above step.
I was having similar problem, My 1st mobile was working fine while the 2nd one was not displaying anything under Watchpower scan menu.
1st device had GPS enabled while the 2nd one GPS was turned off.
issue is resolved by enabling GPS on both devices.
nothing is wrong with your Inverter, if you don't put any load then you won't receive any current from PV, this is how MPPT work.
since you have attached batteries, you're getting about 1.3kw because MPPT Controller is charging your batteries, once batteries are charged, then PV will go back to 0Watt which is normal.