Most of this stuff is not anymore what it was 30 years ago. Especially what you can buy in Thailand, is all from China with different quality, mostly in the lower range.
Once I lived in the UK, and the house had a power cut from time to time. Usually the main breaker would switch off. Probably we drew too much power. But it also happened when nearly nothing was on.
On one occasion, we had the power cut again, but the main breaker was on. Electricity company came, measured, no power. Next day, they started to dig a hole in the street, took them a day, they didn't find anything.
In the end, the electricity guy switched the main breaker off and on again, and instantly the power came back. We looked at each other like idiots.
Neither me nor them have tried to switch the main breaker off, because it was on. That breaker was not a RCD.
Since then, I do not trust these breakers very much.
I don't have a picture of the breaker, but I documented the emergency measures, and I was very proud in these days to provide 230V out of the car battery with a UPS.