Do you have any themes or third party launches on your device?
Do you experience these symptoms if you test your device in safe mode? 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/