With him will I speak mouth to mouth, even apparently, and not in dark speeches; and the similitude of the LORD shall he behold: wherefore then were ye not afraid to speak against my servant Moses? Numbers 12:8 KJV
It is clear from Numbers that a 'similitude' was seen by Moses.
And the LORD spake unto Moses face to face, as a man speaketh unto his friend. Exodus 33:11 KJV
This speaking by 'similitude' is called, in Exodus, 'speaking face to face'.
So it is scriptural to refer to God speaking to Moses 'face to face'.
But Numbers explains in, more detail, what that means. It was a provision whereby God could communicate the wealth of detail which we see set out in Genesis, Exodus, Leviticus, Numbers and Deuteronomy.
We know, of course, that 'God is a Spirit', John 4:24, and that 'no man hath seen God at any time', John 1:18. What Exodus and Numbers reveal is the means whereby God presented a 'face' (that is to say the similitude of a face) in order that a wealth of information could be - accurately - conveyed by word of mouth to the man, Moses.