Siemens SN26M253GB/44 dishwasher

Been to this machine a couple of times.
Customers had several complaints:
1. Only getting a decent wash on the 70º intensive cycle, the rest seemed cold
2. Tablet intermittently not dissolving (does on the intensive cycle, hit and miss on the other cycles)
3. Not draining completely at end of cycle, water level just above the filter. Filter isn’t blocked and water drains off ok at the start of the next cycle.

I replaced the turbidity/temp sensor and checked the temperature on a quick 45º programme. Got to temperature ok.
After that customers seemed to think the heat was better.
However problem 2 & 3 remain.

Regarding the tablet, I asked if putting the tablet at the bottom of dishwasher instead of in the dispenser made any difference. Not received specific feedback on that yet. If it did, I would look to replace the detergent dispenser.
Regarding residual water at end of cycle, wondering if it is normal for this dishwasher? If not, any tips?

At the moment, customers are thinking the dishwasher performance is ok though not brilliant.