3000w Inverter Problems???

I currently own a 2017 Freightliner Cascadia
I have a 3000w inverter installed w/ 300amp inline fuse. Had a 1,500w with 200amp fuse but something went wrong and the #### alarm on it continuously stayed on even withnothing plugged up to it so I replaced itbumped it up to 3,000 w/e..

Prior to the 3,000w inverter I had both a mini fridge and freezer about 700w a piece plugged up and same 700w microwave worked and ran perfect. Was even able to plug up additionalstuff like a hot plate single eye electric burnerat 1,000w. Yes I would unplug everything else just in case but preformed perfect. Even when I would sit and play PlayStation @ 75w and TV @ 50-75w while cooking either in skillet or crockpot @300w and rice cooker @ 75w ran perfectly.

The new problem!!!

Yes I bumped up my refrigerator to a 4.5 cubic feet same microwave @700w. NOW w/ REFRIGERATOR UNPLUGGED!!! Only themicrowave plugged up if I run my microwave at 5 minutes or more the inline breaker (by PowerDrive) trips has to cool for 2-3 minutes before its able to be reset. I cannot run TV and PlayStation at same time w/ refrigerator plugged up. W/ refrigerator unplugged my hot plate sets off low power alarm my George Forman grill @ 1,500w sets off alarm. Rice cooker, crockpot, blender, works fine w/refrigerator plugged up. It’s becoming frustrating obviously TA nor LOVES don’t even service inverters or give advice just pointless.

I’m considering getting a generator or APU to solve the unknown problems. Which do y’all recommend is best?? Or can anyone please tell me what the hell I can do or should do or recommend??

 

Batteries are fairly new recently replaced within a year. Not the batteries 100% sure when I’m home n leave truck off for like 3 days voltage still at 12.5 truck turns over fine. That’s with battery switch on and inverter on I’m sure it’s the connections and inline fuse process of elimination self diagnosis..