Someone else will suggest these steps to you, so you may as well follow them.
The update itself didn't likely cause any of your device's issues, but..
Boot into Recovery & Wipe Cache.
See if your device behaves normally now.
If not,
Boot into Safe Mode & see if the issues continue, if they don't, then it's likely to be a 3rd party app responsible for the problems. Try Uninstalling any recently downloaded apps & see if it's fixed?
Still having trouble, Backup your device with Smart Switch & Boot into Recovery and Factory Reset.
To Wipe Cache & or Factory Reset:
Power of your device & Wait a few seconds.
Press & HOLD the Power +Volume UP buttons until you feel the device vibrate. Release BOTH buttons & wait a couple of seconds until you see the Recovery Menu.
Use the Volume button to Scroll down to Wipe Cache & Select with the Power button.
Wait a few seconds until the Recovery Menu Defaults to "Restart Now".
Your device will Reboot.
Factory Reset is the same as above, but instead of Selecting Wipe Cache, you Select Wipe Data Factory Reset.
⚠️⚠️⚠️
BEFORE you Factory Reset, BACKUP your device with Smart Switch.
When your device Boots up, it will be to the Welcome screen, same as when you first received your device as new.
⚠️You'll need to know your passwords etc, So write them down if you need to⚠️
Hi JoannaWJ, we suggest you to perform safe mode. IN Safe Mode, your phone will not run any third-party apps. This allows you to easily identify and remove the app that may be causing the problem. To enter Safe Mode, please perform the following: 1.First, completely power off the phone. 2.Then, power on the phone and when the Samsung logo appears, press and hold down the Volume down key. and We equest you to follow the steps given by RedDogRabbit. Thank you RedDogRabbit for your steps and suggestions.
No, it's not really a common problem, but I always Boot into Recovery after every Monthly Security Patch Update.
There's a script built in to the Updates, that is supposed to do it for you, but occasionally there's some "ju*nk" left over which can cause some problems.
As for Booting into Safe Mode, while it's true that it disables 3rd party apps, there's nothing that "allows you to easily identify" a potentially problem app.. it's strictly by the process of elimination.
