Hello mizmarsha, Welcome to the Community. We understand how frustrating it is for apps to open on their own. There are some steps to try to correct this behavior.
1. Enable Adaptive Battery - Open the Settings app on your phone and navigate to Battery and device care.
Tap on Battery and then scroll down to tap on More battery settings.
Enable the Adaptive battery option.
2. Restrict Battery Usage for Apps - Long press on the app’s icon and tap on the info icon from the menu that appears.
Tap on Battery and choose Restricted from the following menu.
3. Put Unwanted Apps to Deep Sleep - Open the Settings app on your phone and navigate Battery and device care.
Tap on Battery and then tap Background usage limits.
Go to Deep sleeping apps.
Tap the plus icon in the top right corner, select the apps that you want to put to deep sleep, and then tap on Add.
Additional steps include clearing the cache partition and repairing apps from the recovery menu.
To get to recovery mode: - Turn off phone - Once off, hold down volume up and power buttons simultaneously - When Samsung logo appears, release power button BUT KEEP HOLDING VOLUME UP until the recovery menu appears - Use volume buttons to navigate down to clear cache (NOT CLEAR DATA/ FACTORY RESET) - Use power button to select. - Run the repair apps option and your device will restart.
If all troubleshooting steps do not resolve the apps opening, service is recommended. You can use the following link to find a list of service centers in the U.S. that can do the repair: http://www.samsung.com/us/support/service/location or by calling customer support at 1-800-726-7864.
