[Resolved]  Samsung Wt13j7 Twin Tub — water not draining from Dryer

The water is not draining from the spinner, the pump has already been replaced, I checked fo Blockages found None. The black rubber valve at the entance of the drain pipe inside the spinner is also not sticky.
Sometimes if you lower the drain pipe outlet to ground level it starts to drain the water from the spinner, you can then pick up the drain pipe and it will still drain all the water.
it seems like the pump is getting an air buble because you can hear the pump turning.
can anyone please assist