I set an alarm for 8:55am and it never went off. At 8:58 it was saying that its 38mins until its due to go off.
Ice also had one time alarms just never set, and some issue with the stopwatch.
Alarms are important to me.
What app do you use?
That seems like a possibility. Yeah, LineageOS has some great stock apps, I wish they were more possible outside the OS itself.