I’ve got an Indesit washer that is around 6 years old.
Last night I used it and the washing powder didn’t empty from the drawer into the machine. The clothes were wet, so it wasn’t a problem with the water.
I emptied the tray and cleaned it out and the area behind it. It still didn’t work.
This one uses a steering mechanism on the roof of the soap box to jet the water into the different compartments, so that will be your problem. Remove lid and plug to have a gander.