Is your device stuck in safe mode? Here are a few helpful hints if it is.
Is there a case on the device? This may be causing the issue if the case has an improper fit causing the volume down key to being pressed in.
Do the volume buttons work? Test to see if the volume can be toggled up or down. If the volume can’t be toggled or goes down without pressing anything then there may be physical or liquid damage to the volume buttons. Another way we can test this is with the Sub Keys test. To enable the test you must first go to the dialer and enter *#0*#.
Does the volume down button move freely? If not then this is why the device is stuck in safe mode, have the device checked for physical damage at a core store.