In GM cars (as observed in my last few), the logic is in the head unit: "mic on -> hvac lower", while "hotword detect" uses a different "mic on" method that does not
EDIT, previously "does not" above said "doe snot", which explains the reply below
I never learned to properly touch type, i have my own method, somehow, which uses two fingers of the left hand and three of the right. Spacebar being pressed too soon or too late is, sadly, common :(