Indesit DI61 UK stuck in cycle?

I’d be grateful for any advice.
I have a 5+ year old Indesit DI61 UK (I believe this is the same as an Ariston LSI61) integrated dishwasher, in a flat I bought last year and so I have no instructions for it. Yesterday I opened it at what I thought was the end of the cycle but was apparently too soon, judging by the huge cloud of steam and the water remaining in the bottom. I have manually removed the water with a glass and then mopped out the last bit from by the filter with a cloth. The problem is that it will not let me go to the start of a new cycle to do the next load. There is some kind of mode button which lets me move between 4 settings (I assume stages of the wash but not sure) – normally I turn the machine on, it flashes at position 1, and I press the mode button to make the light at 1 stay on then start it running. Now, the light is already on at 1 and will not move.

Haven’t been able to see any recent posts about this sort of fault although I guess it could be a flood detector in the base?

This happened once before – an engineer came out and said that because the dishwasher hadn’t been properly screwed in to the surround, it had vibrated something to do with the power either too far out or too far in (my partner dealt with it and she can’t remember which).

Because it’s integrated it’s going to be a real pain to take out and put back in, although hopefully it will be a simple and obvious fix if I go that far. Is there likely any way to avoid having to do that?

Thanks in advance,
Paul