Jukebox Duplication

I made a jukebox to play my music, put it down, and put in the disc. Fist, music didn’t work, but that’s already been reported. What really concerned me was when I mined it with an efficiency 4 unbreaking 3 silk touch 1 diamond pickaxe, I got two jukeboxes back. I have duplicated up to 20 jukeboxes so far. Screenshots show me after I have duplicated 10 times