Inverters (especially cheaper Chinese ones) are poor at reporting actual stats. In any case though,
520w of Solar coming in, at 98% efficiency = ~510w.
510w going to loads and charging at 90% efficiency = 459w of usable energy.
199+234w (load+batt charging) = 433w. Its only off by 26w. And this is all rough estimates.
You also can't use the standby consumptions, because you are not in standby/idle! Once you have any load, you are not at idle, and you must account for efficiency. The lower the load the worse the efficiency as well. There is an efficiency curve, and typically peak efficiency is somewhere between 50-70% of max load, usually.