Hi @jansens ,
Is the oven still covered by the manufacturer’s warranty?
If so contact the manufacturer’s customer service centre about the problem and get it fixed under warranty.
If not you may have to pry open the door as best you can so that access to the trim kit screws is possible and you can remove the microwave to make it easier to repair the door latch or the board latch, or both depending on which is broken.
Although most probably you may have to replace the entire door as well (parts found from this webpage) once it becomes available that is.
As you say poor design, especially from a maintenance point of view if the door won’t open and given the cost of the door latch it may be that this might happen frequently.
If the trim weren’t there it would be just a matter of removing the microwave oven cover and then unscrewing the control panel from the inside so that access to the board latch and the door latch is possible so as to release the door.
A quick search online revealed that you are not alone experiencing problems with the door latch on this particular model.