Type AC which have been the standard on domestic for years, either FTO or take many times the rating to trip, if you have even the smallest amount of DC circuit leaking back to the device.
PV's and EV chargers are becoming more common, but even a poorly made phone charger, USB socket outlets or plug top DC transformer could cause this.
Most of the stuff we plug in now a days is AC>DC, gone are the days of the post war copper shortage and a ring of undersized conductors, designed to power two 1 bar heaters...