Please ensure the machine is turned off at the power socket before you do anything.
Have you tried removing the draw? If you pull the draw out on most washers and slightly tilt the draw up and then try and pull further out the draw will come out. (DO NOT USE BRUT FORCE) if it doesn't come out easily then it probably isn't designed to.
If you get the draw out give it a really good wash in hot soapy water, the compartment where the softener goes normally as a piece of plastic that lifts up so you can clean the compartment throughly. Whilst the draw is out also give the inside of the draw compartment a clean out. (PLEASE ENSURE THE POWER IS OF
F) Just for safety.
Once you have cleaned the draw replace it and try a full wash and see if that cleared the problem.