Conditioner compartment does not empty. Why?? Have cleaned the drawer thoroughly and there seem to be no blockages

The conditioner flow to clothes at last rinse so the water inlet reach to this compartment only at this moment
also the water must be with suitable amount to let the siphon small tube to work you can emitat this step by water only to sure it is ok or not
after that every thing related to this problem will be clear
you wellcome