Surprise: IOS hasn't worked (8)

I believe the answer is:

astonish

'surprise' is the definition.
(astonishing is a kind of surprising)

'ios hasn't worked' is the wordplay.
'worked' indicates anagramming the letters.
'ios'+'hasnt'='ioshasnt'
'ioshasnt' is an anagram of 'ASTONISH'.

(Other definitions for astonish that I've seen before include "Stagger" , "'knock for six'?" , "Cause amazement" , "Take by surprise" , "Provoke wonder" .)

I've seen this clue in The Guardian.

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