malfunctioning vs nonfunctional

malfunctioning and nonfunctional both are adjectives.

Word	Noun	Adjective	Verb	Adverb
malfunctioning	No	Yes	No	No
nonfunctional	No	Yes	No	No

As adjectives, malfunctioning and nonfunctional are synonyms defined as:

malfunctioning and nonfunctional: not performing or able to perform its regular function

malfunctioning (adjective)	nonfunctional (adjective)
not performing or able to perform its regular function	not having or performing a function
	not performing or able to perform its regular function