Downloaded apps disappear at 10 PM, reappear in the morning

Why are my apps disappearing from the screen at night? In the morning they are there but app settings for allow notifications need to be reassigned. This has happened over the past two days. I had the phone open and suddenly app non-standard apps disappeared a little past 10 pm. I do not have downtime set, but I noticed that it has downtime defaulted at 10.