Hi
Go to iCloud make sure iCloud back up is on Then backup now over your wifi.
Then go to settings down to reset Restore iPhone back to factory settings.
Set back up over your wifi when it asks if you want to use iCloud backup Say yes to get your apps and data back this will get rid of any bugs.
But 16G is not a lot of storage upgrade iPhone when you can to 64G/128G
Cheers
Brian 🇬-1F1E7;