Note on Janome foot controllers. Put your foot control on a towel on the counter, take it apart and check for lint and pet hair. (the Towel keeps screws from running off)
Take photos of sequence of taking it apart, so you remember when putting it back together. Just like my machine, I was amazed how much lint was in my pedal. Of course, you don't have to clean your foot pedal until it starts acting up, where you machine needs cleaning sometimes during and after each project.