No, don't hammer it.
The filter part just pulls out, something is jamming it into the pump.
Unplug the appliance from the wall socket.
Open the door and take the retaining ring holding the door seal to the front panel off, then peel the door seal off the front panel.
Take the screws holding the door interlock in place out.
Underneath the front panel, take the 3 bolts out.
Press downward on the front panel and lift it away.
You now have full access to the pump and filter housing.
Take the hoses off the filter housing, take the wires off the pump and take the unit out of the machine.
Look into the filter housing ports where the hoses were attached. You should be able to see what debris is holding the filter in place. Take this out, then the filter should come out for cleaning.
Ensure you take all the debris out and that the pump impellor is free to turn. Check inside the hoses for more debris and clean it out if there's anything there.
Reassemble the machine then try it again.
Hope this helps.