It sounds to me like maybe you lost all your 12 volt power when the generator ran out of gas. That tells me all your 12 volt is coming off the power converter and not the battery.
I would suspect that maybe your battery is not hooked up correctly or you have a wiring issue. If the battery is not hooked up, the monitor panel will show it as a dead battery.
If you use shorepower all the time it would be easy to not be aware of such a battery issue. You would have to make it a point of checking things like lights while not plugged into shorepower to see if your battery is hooked up and working.
FAA A&P mechanic, ex-RV dealer parts dept
Retired B-52 Gunner/Flight Examiner, B-52 Crew Chief
2016 Jayco Eagle HT 29.5 FBDS w/ 15,000 BTU AC, 50 amp service, upgraded counter top, thermal pane windows, elec. stab jacks, outside grill, backup camera and MORryde pin box.
2011 GMC 2500HD DURAMAX/ ALLISON