i have a HTC M9. up until a few weeks ago, i have been happily using an alarm called alarm clock xtreme, a free app. but then my phone stopped sounding out the alarms. i tried re-installing it but that didn't help. so then i installed alarm clock plus. same issue. my alarm will not sound off in the morning. i discovered that the alarms will work if i set them within an hour. so if the phone is sitting for an extended period of time, the alarm will not go off unless i 'wake' it up near the time the alarm was set. i don't remember installing anything just before this issue began, but i have battery doctor and clean sweeper on my phone and hypothesized that one or both must be hibernating these alarm apps if the phone is not being used for a period of time. and i'm always installing updates on my apps so maybe a recent update is triggering this. so i put alarm clock plus on battery doctor's "ignore list" but that didn't help. and then i found this when running through clean sweeper's settings: there is a section where you can choose "Recommended to keep awake". so of course i put alarm clock plus on there. and when i click on its icon, a popup menu asks "Hibernate Alarm Clock Plus to save power?" and just underneath that in grayscale it says "Alarms only work when active". what does that mean? does that mean that when the screen goes dark/hibernates/whatever that no alarms will sound even if it's on this ignore list? i do i fix this? is it definitely clean sweeper or battery doctor causing this or something else?