Maybe u try playing around with the little MCB switches and try to narrow down which circuit is causing the trip during lightning?

To test how good is your electrical grounding, get a MEGA tester or insulation tester. Calculation based on OHM.

MCB detects overcurrent. Say, a 2.5HP aircon connected to 10A MCB, MCB will trip.
ELCB detects if any current running in the Earth conductor
RCCB detects residue current between L&N.

Earth Resistivity (Electrical Grounding) test using Earth Tester. Calculated in Ohm, the lower the ohm the better it is.

Insulation Tester (Mega Tester) is test the insulation capability of the cables. Measured in MOhm. The higher it is, the better.

Both Earth tester and insulation tester are not cheap at hundreds.

The original RCCB from the house developer is 100mA. Trip like hell. Change it to better brand Hager 30mA. Less trip.

So it doesn't logic to me that 100mA give less problem. And compromise the safety.

You can get it at any electrical shop. It is not branded item now.