On the off chance anyone else runs into this issue…
Windows reserves Ctrl-Shift-# and Left Alt-Shift-# for changing keyboard layouts and keyboard input languages, even if you have never used these feature, in which case Ctrl-Shift-0 and Left Alt-Shift-0 are still assigned as hotkeys and that means Windows will not allow those key combos to get to sent to WoW. To disable this windows hotkey on Windows 10 type “Advanced keyboard Settings” into the search bar and select “Input language Hotkeys” link and in the next window click the Change Key Sequence button and unassign the 2 options.
Until you disable these you may not be able to use Ctrl-Shift-0 or Alt-shift-0 to activate WoW macros.