soap door does not open automatically

This may be a portion of a bigger problem. The control knob started to become difficult to turn about the same time that I noticed the soap door stopped opening during the wash cycle. I removed the inner door and determined there was something wrong with either the draw bar or the actuator, like a piece was broken, but the spring appeared intact. Now I wonder if it was the latch kit. I was able to make the control knob work again but not like before. Otherwise the dishwasher runs well, I just have to put a bunch of soap in and start it immediately. Not sure which parts I need. Any help is most appreciated.
Thanks!