matter of law vs question of law

matter of law and question of law both are nouns.

Word	Noun	Adjective	Verb	Adverb
matter of law	Yes	No	No	No
question of law	Yes	No	No	No

As nouns, matter of law and question of law are synonyms defined as:

matter of law and question of law: a disputed legal contention that is generally left for a judge to decide

matter of law (noun)	question of law (noun)
a disputed legal contention that is generally left for a judge to decide	a disputed legal contention that is generally left for a judge to decide