Menu and back button on Samsung Galaxy S6 stopped working. How can I get them back?

[AC Question]

The app manager/menu button (left of home) and back button have stopped working completely. I've restarted my phone several times and went to tmobile, but of course when someone there restarted it, it started working again. Now 5 hours later I had to turn off my phone and when I turned it back on, those functions aren't working again. Super frustrating and really want to avoid having to go through warranty and the time to actualize a new phone again with all my stuff. Any suggestions on how to get these working again?

 

[STARGATE]

First time I've heard of this problem, so I'm not sure how to help.
Are you still within the 14 days to exchange the phone?
If not, maybe a factory reset will help.

Sent From my Gold Platinum Galaxy S6 Edge

 

[Ajr08011]

Unfortunately I'm way past the 14 days. Hoping there's a solution outside a factory reset but may have to.

 

[Kelly Kearns]

Unfortunately I'm way past the 14 days. Hoping there's a solution outside a factory reset but may have to.

If that doesn't work, the other option, if you do not want a warranty exchange phone, is to send it to Samsung. Not only will they check this issue, but will check the phone from top to bottom, take off the software, install it again (not just a reflash).