Are you referring to the inlet hose from the garden hose pipe or the outlet hose which is under high pressure?
So the pressure washer hose is connected to the power washer ok via the screw thread but the other end wont stay fitted into the washer handle\gun?
If I am correct can you confirm you can see the washer on the hose connector which pushes into the lance, if its present depending on the age of the unit you could arrange for a warranty replacement of the lance, or if its out of warranty order a replacement lance which is around £20 here.
I just wanted to follow up and check if you required any further assistance?
I havent heard from you in a few days, and I just wanted to follow up and check if you required any further assistance?