Door latch-reversed logic?

My Sharp dishwasher failed to start the other day. Giving a single beep each time I tried to select a program.

I tried to close the door to cycle the program incase it hadn’t finished its last wash (family frequently opening it and taking stuff out).

It wouldn’t latch. No amount of pushing in would get the door to latch. Striker good, seal good, hinges good, no objects or obstructions.

So I decided to trigger the latch with a flat butter knife to see if the mechanism was jammed. It moved through fine and the contact switch could be heard clicking. Then the program lights went out. I cycled the power but still nothing until the unit started running with the door open.

I found that when I have the power on the machine tries to start its program even with the door open. It’s not just the drain pump but actual wash cycle comes on.

If i place something in the latch it goes off and appears in the open door mode.

So now it is as if the logic circuit is reversed. Works with door open, not with door closed (simulated with something inserted in catch).

Being as though the catch isn’t latching and the safety switch logic is reversed, can I conclude it’s a latch problem?

Rather than a board problem?

The machine isn’t that old but I’ve identified the latch at £16 new delivered with integral switch.