Possibly a stupid question but, you have made sure that all your repos are comming from the same mirror correct?  And that you are making sure to do an xbps-install -S to resync?  I remember when I was jumping between mirrors I only changed one which gave me troubles due to different repos.

Now that I check your post I realize you said you did:
>xbps-install cinnamon NetworkManager network-manager-applet wireless-tools nano

Add the -S switch to make sure the repos are properly in sync so...
xbps-install -S cinnamon NetworkManager network-manager-applet wireless-tools nano
The above should work if syncing was the issue... Good Luck.