Hotpoint BFI680 error,….

Firstly Hello everyone.

On Friday the dishwasher kept tripping the RCD. I took it apart and there was some water in the sump,… found that the central connection from the high pressure sensor to the bottom arm was loose, tightened, dried it out and tested. On Saturday upon start up she drained and filled as normal, then went to the filter block error, ‘Auto’ and ‘Crystal’ LEDs flashing, but did not appear to start the main recirc pump.

The circuit does not appear to be blocked; also this all started with a leak.
The recirc pump is not coming on. Removed and tested the pump, it is powering and turning OK, as is the rotary valve.

Can anyone advise how fast this pump and the rotary valve turn? It did not seem particularly fast, I was conscious that when i tested the motor/pump on the ground, it did not recoil on startup, although it did rotate?

Is the high pressure sensor NC (normally closed) and then opens when the pump starts (when the pressure rises), or does it only go to open in the the event of a blockage? Mine seems to be NC, when tested (dishwasher off). Bypassed the high pressure sensor, and still get the same error, so the sensor does not appear to be inhibiting the pump from running.
The control board pump relay is OK.

Possibilities:-
Something is inhibiting the motor start sequence (but not throwing up and error)?
the motor is starting but with too low a pressure/speed and the controller thinks the circuit must be blocked.I did not think the pump looked particularly fast when i powered it up.
Other?

I welcome your comments and advice.

Keith