Lamona LAM8301 not fully draining sometimes

We have a 9 year old Lamona LAM8301 dishwasher that is used regularly and cleaned regularly. We always use the Eco cycle, expect when we clean it when we use the 70 degrees cycle. We also always take the filter out at the end of each cycle and run it under the cold tap to clean it.

Sometimes, when we pull the filter out, there is still quite a lot of water in the trap it sits in. Also, sometimes the drain part at the end of the cycle sometimes seems to take a long time. Starting the cycle again is the only way to get it to drain fully – stopping the cycle it after it has drained.

We have taken off the connector under the sink to see if the hose is blocked, but it isn’t.

Any suggestions as to what we can do next? It works fine otherwise.