If the door isnt opening during the cycle but does freely open if you do it yourself then you need to remove the outer door panel.
From there you will see the back of the dispenser unit. There you will see a wiring block going to a relay lever. You need to test that with a multi meter for contonuity. If theres no contonuity then the relay for the dispenser is faulty and for this you need to replace the complete dispenser unit.
But if the relay on there tests ok then the control board will be the issue here im afraid.
So try the above and see what you find if you can as for this fault then its either the dispenser itself or the control board and if you have a multi meter you can find out which is the fault here.