Can't overwrite some keys

[ghost]

My MX1 key, after installation, has the Play/Pause functionality and i can't set it to something else in xbindkeys. There are other keys that act the same while others i can set up just fine.

Get Key: Mod2 + XF86AudioPlay | m:0x10 + c:172

xev result for keys that don't work:

FocusOut event, serial 41, synthetic NO, window 0x5800001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 41, synthetic NO, window 0x5800001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 41, synthetic NO, window 0x0,
    keys:  1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   16  0   0   0   0   0   0   0   0   0   0   

KeyRelease event, serial 41, synthetic NO, window 0x5800001,
    root 0x1dd, subw 0x0, time 2889464, (1169,-38), root:(1169,804),
    state 0x10, keycode 172 (keysym 0x1008ff14, XF86AudioPlay), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

xev result for keys that work:

KeyPress event, serial 41, synthetic NO, window 0x5800001,
    root 0x1dd, subw 0x0, time 3459210, (1306,95), root:(1306,937),
    state 0x10, keycode 186 (keysym 0xffdd, F32), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 41, synthetic NO, window 0x5800001,
    root 0x1dd, subw 0x0, time 3459346, (1306,95), root:(1306,937),
    state 0x10, keycode 186 (keysym 0xffdd, F32), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

The files from config are all in the right place and i've run xmodmap ~/.Xmodmap too.

Is this how it's supposed to be? Any ways to "fix" this?