Honestly, without understanding your implementation, this can always get a little interesting. For instance, do you have cross-device tracking implemented (this only allows you to follow your users from mobile to web, and not the other way around). The other thing I notice is the split you're doing between Mobile Web and Desktop. That may be where you're seeing your duplication right there, because unless I'm mistaken, Mobile Web is just the responsive version of your Desktop environment, am I correct? This is where you may be double dipping, and even your best efforts to keep the two separate may be working against you.
Right now, that's my best guess without knowing more. Hope that helps.