don't downgrade bro ..it's for few reasons.. 1st of all if your device support knox security service. . then it will tripped , you may have to compensate 4 or 5 built-in useful features , security of system hamper and none of the service center will take any responsibility if by chance anything happened..
To resolve auto restart issue please follow below given steps: Go to Settings > General management > Reset > Turn off auto start.
For further assistance, register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
I just went to the service center with the same issue they told me it's related to motherboard and I have to replace it, but I have never dropped my phone and I have never used any other charger than the one they provided.. I'm pretty sure it's just software issue but they just want me to change motherboard
