[Grace Baker Moderator February 17, 2020 at 10:35 am Grace Baker Moderator]

Hey, Thanks for reaching out to us.

For Samsung Knox devices, navigate to Policies->Android-> Restrictions-> Allow Device Functionality and disable the ‘Power Off’ option to block the users from turning off the device.
By default, it is permitted to turn off the device.

Kindly use the help link for more insights.

Cheers!
Grace Baker
Hexnode MDM