BEKO DW603 Dishwasher Fills with water as soon press start and stops

Hi all, I hope you can help me

We have quite an old dishwasher used every day.

What happens is:
. I put on the dishwasher (Any programme)
. The dishwasher gets rid of the old dishwater which is fine ( So pumps etc works) BUT:
. After that the dishwasher starts filling again (from a round opening top left side?)
. It just fills until the sensor stops the filling which leaves around 4 litres of water at the bottom.
. After that nothing happens. Sometimes I could hear a numb thumping noise.
. I reset the machine and select another programme and the same happens and stops.

First I went through the hassle thinking I had a blockage issue so opened the dishwasher and checked the filters and whether the filter pump was blocked (an absolute hell to take that off as it was a bayonet type)
No blockage....connected everything again and tried again to find out that the above is happening.
There seems no water to come through the arms but only through that hole top left of which I think there should be no water coming through at all. Unless any of you friends have any idea.
If so and anyone had to deal with this please let me know.

Thanks in Advance

Hi Denix, did you get your dishwasher sorted as I seem to have a similar issue to yours?

Hi Denix / Ajkayb

Did you get to the bottom of this mine has started doing exactly the same as yours and prior to taking it out and stripping a heads up would be good.

Thanks