Deleting completed jobs on Epson WorkForce 30

I am not able to delete completed jobs using my Epson WorkForce 30 printer. I click on “jobs completed”, see a list of completed jobs, and if I want to delete just 3 of them, I click on “delete” but nothing happens. I have contacted Epson support and the solution they gave me did not work. They said it might be an OS problem. I use CUPS but it deletes all the completed jobs. Does the printer keep a permanent list of completed jobs so that I can’t delete any?