I regularly try out the betas and for some time the persistent alarms have not been reliable on my phone. The initial alarm sounds then sometimes the repeat alarm will sound when it is due sometimes it doesn't.

Today while still on build 676 an alarm sounded when it was due. The persistent setting is 15 mins and it was over 90 minutes before I heard the alarm then it repeated at 15 mins before I dismissed it.

Other times the alarm won't repeat until I unlock the phone often at this point it will sound the alarm twice.

I have sent a couple of logs from an earlier build but not had feedback yet.

I have just downloaded 678 to see if is any better.