Crossword Genius

Place roughly the wrong way round, causing malfunction (3,2)

Ross

I believe the answer is:

act up

'malfunction' is the definition.
(I've seen this before)

'place roughly the wrong way round' is the wordplay.
'place' becomes 'put' (synonyms).
'roughly' becomes 'ca' (abbreviation for circa).
'the wrong way round' is a reversal indicator.
'put'+'ca'='putca'
'putca' written backwards gives 'ACT UP'.

'causing' acts as a link.

(Other definitions for act up that I've seen before include "Behave badly (colloq.)" , "Behave badly, cause trouble - like thespian?" , "Mess about" , "Behave like a brat" , "create fireworks display?" .)

I've seen this clue in The Times.
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