New Victron Multi-Plus II - No 120v

[Bobkat11208]

We had a new Multi-Plus II 12/3000/120 charger/inverter installed today and installer (who I would recommend) and I have an issue we're looking for insight on.  We replaced a 2004 Magnum MSW 2000.  

Proper sized wiring ran from ATS to Inverter to Panel to handle increased load.  Plugged into 50a shore power properly wired (2-120v legs). Reading 240v across transfer switch and 120 on each leg/side in Main Panel in bedroom as well as at Transfer Switch.  Both Cerbo and shunt reading proper information/status (regardless of shore or generator power).  App shows "NO AC Input" (but does show "AC Output" )of approximately 1350 watts with both ACs on.  FLA battery bank (450Ah-4-6v GC2 batteries new in February 2024) showing Storage charge phase having going through the proper charging sequence.

All 12v works.  Both 120v ACs-front and rear - work.  

Problem:  Running on either generator or shore power, there is NO 120v to ANY outlet or microwave (again there is power at the Main Panel.)  First thing was to check GFCI (20a) in Lav. 
There is no power coming into it and consequently any downstream outlets on that circuit or any 120v outlet in the coach. No power to microwave also.  

Any thoughts/direction from those who have installed similar?  Thanks!

Edited August 30 by Bobkat11208
Clarified problem statement

[Bobkat11208]

You all can stand down.  😀  Found the issue (wire 'going no where'-that's on me!) was the culprit.  Connected and the new Victron Multiplus II, Cerbo GX communications interface and Shunt all are working in harmony as is 120VAC.  I have full vision of what the Inverter/Charger and batteries are doing, as they are doing it, right on my phone via both Bluetooth and the Internet.  Much better than the Magnum ME2012.

On another note, I have a Magnum 2012 if anyone wants it and/or it's internals.