I’ve been having some issues with the timer setting recently as well. I actually started a post a few days back to see if anyone was having the same problem.
Basically I’m runnning a very simple sketch and have found that is seems to work from about 6:00AM Pacific Time to sometime in the afternoon where is stops working. I think it is before about 6:00 PM because it doesn’t seem to work after I get home from the office or during the evening up to the point when I go to bed which is around 11:00PM. Works in the morning again when I get up the next day. I’m in the process of trying to figure out approximately when that occurs by testing it every hour. Try it early in the day and see if you can recreate the same issue. I posted the sketch in the other post if that helps. Good luck.