What is this on the lock screen..the black thing and it has happenes multiple times. It gets stuck and cant remove it unless i fc the app.
Which app are you referring to?
Yes, what app? I can't see if I can duplicate your issue unless I know which app it is and if I can't duplicate it, then we can't fix it.
Please also tell us if it happens ever time with this app or if it happens during some specific scenario. The more info you can give us, the better.
Do you want to react to the background of the locked screen when playing music will become the album cover?
If the phone is playing music and setting cover, the lock screen will display the blurred cover pattern.
This automatic wallpaper according to the cover of the music you're listening doesn't work with you have enable the slideshow wallpaper.