Yeah, I tried various ways of saying frag grenade. I even repeated fragmentation grenade, then would say nade, rinse and repeat many times to get the voice recognition to adapt. It wasn't having it. I wasn't in a noisy environment at the time (I live next to the Airforce Base LOL). I'll try the noise suppression anyway, though the settings have been the same since I stopped pc gaming over a year and a half ago when it worked fine. I think it's Windows 10's fault as there is zero reason for the voice recognition to have reset the progress like it did.
Edit: Wrote a big edit but then discovered that I had NOT put Frag by itself in the command. Another one, Melee, didn't work until I enabled "restricted continuous speech". I hacw no idea what it actually means or how it differs from simply "continuous speech", but it seemed to do the trick. Pushing foward till I get this all sorted.