Two Calendar alerts not working since iOS 9 update
I was able to duplicate this issue on iOS 9.0.2, and these steps worked for me:
- Tap "Second Alert"
- Set it to "None" (at the top)
- Tap "Second Alert" again
- Set it to the desired time.
This appears to be fixed on iOS 9.1 for me. Do a backup just in case your upgrade goes south, but my upgrades were all 15 minutes of waiting during reboots once the download was done.