Update:
I went up top and checked the connections, I am 90% certain the panels are incorrectly connected. Instead of doing 2S1P they decided to go 4S and not sure about the P (kinda messy wiring). I also noticed the 2Series may have the +/- connected wrong! so positive to negative in short making 10 out of 20 panels out of service and risk of damage to overheating and such. Today they are closed but tomorrow I will be calling them to see if they can fix the issue. That's why im getting a max of 4.8kw even when batteries are not full and house having a load or not (10 * 450w would be around 4.5kw)
Hopefully that's the issue