Sounds like sneezing is controversial (2,5)
I believe the answer is:
at issue
'controversial' is the definition.
(thesaurus)
'sounds like sneezing is' is the wordplay.
I cannot really understand how this works, but
'is' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for at issue that I've seen before include "Being discussed or disputed" , "Questionable" , "under debate" , "in dispute" , "In question, under discussion" .)