I am finding that there are a number of settings on my phone that keeps reverting from what I selected back to the standard settings. I tested it out and it seems to revert each time I restart my phone. Is this a bug with my device or a systematic issue?

I do not want the calendar notifications in my status bar, and I have gone in and Set alerts & notifications to OFF AND I unchecked "Notifications While screen is off" Each time I restart my phone, these settings have reverted. Something similar is happening with my WiFi settings, and I am guessing others that I just haven't noticed.