Brandt Dishwasher VF400JU1/B

This DW is overfilling. I can opereate the presure switch manualy when the DW is filling and first click the motor turns and starts washing.
Second click the presure switch then empties all fine.

I have taken out the presure tube box and cleaned, but it keeps overfilling and never builds up enough presure to switch the presure switch.

There are two small manufactured holes with little stems in the box and these seem to go nowhere ! the third bigger stem obvoiously links to the presure switch hose.

What I did find was there was no screw holding the pressure box to the fixing point and it was just a push fit has something else been left off ??

Any ideas

Thanks