Stop at an early stage trouble behind input (3,2,3,3)
I believe the answer is:
nip in the bud
'stop' is the definition.
(thesaurus)
'trouble behind input' is the wordplay.
'trouble' is an anagram indicator.
'behind'+'input'='behindinput'
'behindinput' anagrammed gives 'NIP IN THE BUD'.
'at an early stage' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for nip in the bud that I've seen before include "evidence of springtime frost?" , "Put an end to something in initial stages" , "Prevent before growth occurs" , "stop early on" , "close early" .)