Washing machine filter always full of water please help

Hi, I have a Bush washing machine and it worked well for a few months. We then had a few sink blockages and during that time the washing machine drum filled with water. A plumber sorted out our sink and the machine was ok. However, for the past few months the sink is fine but the washing machine filter constantly fills with water so we need to drain it every time we need to do a wash. This is obviously not ideal as the water smells a lot and I am constantly having to get towels soaking with this dirty water. If I don’t do this and run a wash the water leaks from the filter and even seeped down into the neighbours. We had a plumber in again and he drained the pipes but this did not solve the problem. Please please help!