THIS will be far more important than putting less clothes in
No I'm not talking about that filter, there will be another one, much larger THERE ARE TWO FILTERS! its this bigger one than needs cleaning occasionally, if this one is clogged it won't matter that you are putting less clothes in, you will be wasting £££ every time you use it. Because the cycle will last longer and longer
Serious, check the large filter at the bottom of the machine, it should be the first thing you do if the machine isn't working as it should. If you don't do this you will continue to burn money. It's not hard, you open the panel, unclip the filter, pull out the box, defluff that as best you can and run it under a tap to get rid of the rest and then let it dry.