Electrical issues help

If you just had the fridge replaced then call the outfit that replaced your fridge - it's possible they didn't wire it correctly.

Do you have to plug the shoreline cord into the RV when using the generator?

Does the microwave work ok when plugged in to 30 amp.

Have you used this 30 amp outlet before?

Verify 12V stays present.
After that I would take a close look at the GFCI that protects that circuit (if it has one).

Display going dark, means no 12 volts DC.
When you plug into 120 volts AC the converter takes over from battery power. When you plug the refer into a separate receptacle to feed the refer, the battery is supplying power and it works. When you plug in using the shore power cord, the 12volts should try to come from the converter which it is not.
This could be a converter problem

Suggest you post the Make/Model of the Fridge here, and check the installation instructions for wiring etc. www.bryantrv.com is Chris' site and he has lots of manuals if you don't. Did you do the installation or have it done?

Remember, the Panel is 12 Volts DC. If you Battery Switch is Off, or your Battery is Dead, or your Converter isn't Working or properly Wired. Fridge won't work. Its "muscles" (the cooling part) needs LPG or 120 Volts AC, but the "brain" part (tells muscles what to do when) needs 12VDC

Thanks for the responses. To clarify, when it cuts out the display goes dark. I guess I'm assuming it's no longer cooling. As long as I'm plugged into 30 amp the display will only flicker when I hit power. It works fine with an extension cord or with gas as long as the genie isn't running or 30 amp plugged in. The converter sounds like a good place to start. I'm still open to any suggestions. Thanks!

I think the problem is the 120 volt connection.> Try a trouble lamp (Drop cord lamp) at least 60 watts in that outlet.. Sounds like there is no 120 to the outlet, thus the frigde is naturally switching to GAS.

12 volt issues, gas would not work either.

please clarify what "It works fine if I plug it into a separate 110v outlet" means. is this using an adapter on the 30amp cord or pulling the fridge plug and using an extension cord?

when you say it cuts out does this mean the display is dark? or doesn't cool?

if it is working if the fridge is into a separate 110 extension cord then there is now power at that outlet, check breakers as mentioned but also check GFCI outlets, sometimes they are not very visable

get a plugin outlet test and check all outlets

Your 12 volt DC is not "completely" separate from your 120 volt system. You have a converter that changes the 120 volt to 12 volts DC.
I would start by locating the converter. Test the 12 volt system. It could be the converter causing the issue. It could be having issues with how the battery gets charged. Some older units have an internal relay.
It could also be losing 120 volts to the refer. Try resetting the rig's circuit breakers. Turn all off applying light pressure toward off. Then turn on main breaker, if equipped, followed by the other breakers one at a time.
Locate make and model of the converter.