How come my lg g3 alarm doesn't stay on long because it dismisses itself?

[AC Question]

Hello. I have an lg g3 phone and I think it has lollipop. I researched my problem and saw problems about alarms not sounding in do not disturb mode but thats not my problem. My problem is that I want to keep my alarm ringing until I manually turn it off. I woke up this morning at 9 when i meant to wake up at 7 and saw that it dismissed itself. I tested and saw that my alarm turns on but only for one minute then dismisses itself . I want to keep my alarm on and manually dismiss it because my alarm I can't wake me up if it only sounds for a short period of time. How does one go about fixing this problem so it keeps ringing until I turn it off?