Timer problems. Although I have never used it, I think the "Minute Start" function is

Question

Although I have never used it, I think the "Minute Start" function is operating.Whatever time I set, the machine will only run for a minute at a time. I have to keep pressing the "start" button to continue to the end of selected time.I haven't really tried anything to correct this, as I have no idea where to start! Any ideas?