Thank you for reaching out. If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identity and remove the app that may be causing the problem. Give this link a try: https://www.samsung.com/us/support/answer/ANS00062983/
Next, I would recommend wiping the cache partition on your device. The system cache partition stores temporary system data. It's supposed to allow the system to access apps more quickly and efficiently, but sometimes things get cluttered and outdated, so a periodic cache clearing can help make the system run more smoothly. Give these steps a try:
Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the Android logo displays, release all three keys.
An 'Installing system update' message will show for 30 - 60 seconds before the Android system recovery menu options appear.
Press the Volume down key several times to highlight wipe cache partition.
Press Power key to select.
Press the Volume down key to highlight yes, them and press the Power key to select.
When the wipe cache partition is complete, Reboot system now is highlighted.
Press the Power key to restart the device.
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