I did a little more testing, and this is
what I am seeing:
Alt+shift+0 does nothing
for me when I use the 0 as part of the number pad section of the keyboard,
but does work when I use the 0 above the letters.
I do have the same
experience that you have, where after creating a new keyword set
alt+shift+0 works (provided that I use the 0 above the letters), but alt+0
does nothing.
Alt+shift+0 above the
letters causes a windows beep sound for some reason, but does go to the
prior keyword set
I tried this on a Gigabyte Aero 15x
laptop with built in keyboard and also a Bluetooth connected Logitech K375s
with the same results.
If you need me to try anything else out
just let me know.