Miele G977 plus dishwasher inlet/drain

Initially this just-out-of-warranty machine was flashing “inlet/drain”.

It drained out OK, but the fault would occur about 8 seconds into the fill.

I checked the water pressure and fill hose filter, both OK.
Suspected it may be the reed switch. On removal, the glass capsule was in two pieces. New reed switch soldered in.

Now it fills OK, but after filling, it just sits there silently for about 5 minutes, before flashing “inlet/drain” again.

There are no obstructions in the wash motor nor are there any signs of damage to the pcb.

By leaving the prog selector in its program setting after it has filled, switching off at the on/off switch, pressing and holding the start button and switching back on, I can get it into some sort of diagnostic mode and after a couple of presses of start it ramps up the wash motor, but then with the inlet/drain light permanently on. (I don’t generally just go pressing buttons willy-nilly, but on this occasion I just did!)

Does anyone have the correct diagnostic procedure or any tech info they could accidentally email me, please?
Or any other clues? (I’ve exhausted my search of other postings on this!)

Thanks,
Pigpen.