Printing too late and stop too early

Hello!
I have my 3d printer bit it starts printing too late and stop too early and continues to the end point, how could I fix this problem?

How are you turning the printer on and off? Are you maybe using dispenseware? IRC5 controller?

hi! , im turning the printer with the flexpendant Im using IRC5 Controller!

Set/reset DO? TriggL or TriggJ could be best option.