" " is not a blank/null rather it is a space... if you want a Null use ""

However COUNTA will still count Nulls as valid.

Given your range is non contiguous things are a little more convoluted though you could just add the three together:

=(Q9<>"")+(AH9<>"")+(AJ9<>"")

(with contiguous ranges you can use COUNTIF(range,"*?") ... or even COUNTA less COUNTBLANK given the latter treats Nulls as blanks)