Not familiar with Siemens machines but sounds like a board fault to me.
One of those calls where ‘Its doing this and that and this’ But you never can recreate the fault.
Complaint of:
Stops dead sometimes on the rinse
Sometimes the programme runs through the stop position
Sometimes the programme is too short although she always uses the main wash.
And why is it these calls are always a friend of yer mums. 🙄
Check water level control Tony – can run on if it thinks it’s still full at programme end. Otherwise, being an AKO timer/digiboard combined unit, a lot of the Hotpoint logic can be applied to fault finding.