About a few months I fly to Bangkok, so I have a short transfer at Dubai airport. But when I arrive at Dubai airport, will my luggage be checked by the customs on Dubai? I don't get it, my luggage is already checked at Düsseldorf, so why a second time at Dubai airport?
Even if you are in transfer Dubai Customs may check you baggage-- there are cases of passengers in transit being caught with illegal drugs in their baggage-- they are then subject to UAE law.