There are several conditions that can create the Earth leakage you are describing. With your AEG I'd suggest you pull it out and check for water leaks. Remove the side panels so you can see the workings underneath, pay particular attention to the water hose that supplys the bottom spray bar as these can split or weep, dripping water on to the heater element and causing the RCD trip condition. With the panels removed, and power isolated, deal with any moisture you find and let everything dry out thoroughly overnight. Run the machine and see if things have improved enough not to trip the RCD, then keep an eye out for leaks when running to see if you can spot any.. repair as nescesary.
Rupert
December 2019