One of the more common root causes of problems like slow/sluggish behavior, random device restarts, freezing, unexpected errors and other unexpected impacts are caused by 3rd party applications. Testing the device in safe mode can help isolate and eliminate 3rd party apps as the source of a customer's frustration.
For the S8 and above, Samsung has more user-friendly ways of booting the device into Safe mode:
1. Press and hold the Power button until you receive the on-screen options. (Power off, Restart, and Emergency mode)
2. Press and hold the on-screen Power-off option until Safe mode appears.
3. Once Safe mode appears, select it and the device will reboot in Safe mode.
Note: You can also use Bixby to boot into Safe Mode as well by remember you must have a Samsung account active on the device before you can utilize Bixby. Once you voice wake up Bixby, just state "Safe Mode" and it will bring up the above picture.