Washing machine is fine

10 days ago the washing machine refused to spin. We called for help and this morning a technician came. Based on our description and searching the web we thought it would be a problem with the pump.
We were wrong.
First thing he asked was whether we emptied the filter. We did but apparently there was some more inside to be evacuated. He opened the filter and found more of that blue thing we already removed.
It was as simple as emptying the filter and we called a technician for that.
I asked him to check for anything else leaking, which he did, but he didn't find anything.
It was just the filter!!!!
I felt the same way as when you call IT and suddenly your computer works perfectly. Stupid!!!!