After writing something & finish with it , like a YouTube comment for example, the keyboared doesn't go away anyone knows how to fix that ? Note9 Android 10

The latest update ( one UI ) is nice and easy,  but it took a lot of my note 8 essence,  I can't use the split screenusing the camera is not as easy as beforecan't Customise the contact's notificationsthe gallery is very blandnever thought i'de say t...