Cooler Master does not produce PSUs - they hire companies to make them, then slap their label on it. I think Thermal Master is owned by them, though.
That's a bad PSU. Note that it doesn't actually say "500 watts" anywhere - they claim that 500 is just 'part of the model number' if you complain.
20A@12V is 240W. The whole PSU is maybe 300W, and probably can't be trusted to output that reliably and in spec. Replace ASAP.
Passive PF, more current on minor rails than 12V, and bad english are all more bad signs.