Help with my Lumia 928?

[arcticfox179]

Okay, so last week i got a refurbished lumia 928 off ebay. Been working fine and couldnt complain until today. Then it started to act strange. Suddenly, the power button no longer wakes it up/ puts it to sleep, the notification quick access apps disappear, and the battery saver settings start being changed. Soft resets will only fix at most 2 of these problems. So my question is, is there a way to fix this other than replacing it or performing a complete factory reset?

 

[MarineDawg]

Does a long press of the power button still prompt for shut down?