To prevent Power off while phone is locked

[Cicap]

There is a security issue for all Samsung phones: the thief can acces the Power off/Restart menu. A solution, verified on my A71 is an app from the Google Play, called lockIO, which prevents Power off, Restart or Safe mode without a password! 

[Sidhabhi]

No need of any app..when your device is in lock mode,no one can turn it off without using set biometrics/pin/pattern..even you can try it

Also turn on find my mobile option,so that you can reset device password..

[Š]

Settings> Lock screen> Secure Lock settings> Turn on "Lock network and security"

[Sidhabhi]

Yes 👍