I have the BTS Edition and Buds, and after an update just occurred the theme that installed from the NFC scan from the Buds case has disappeared. This included the wallpaper, dynamic lockscreen, icons, etc. The Purple edition that the phone came with is in my Themes but not this one. When I try to re-scan the Buds case it tells me it can't read it.
I really liked that Theme and want it back!
I figured it out!
If you pull down your menu bar you should see "Samsung Galaxy Friends BTS Smart Buds Cover" and a down arrow. Tap it and a Settings wheel will show. Tap that and you will get slider bars to activate the Buds content.
I got everything back!