Dear Adrian and Alban,
Thanks for the suggestions.
I revisited the entire tables, triggers related to the tables. I did not find anything strange.
But, I removed all the rows from the cf_user_question_link and inserted relevant rows into the table from cf_question.
Also, I recreated the function without the update and deployed it.
Now the trigger function works as expected ( when a new row is inserted into the cf_question, a row with necessary fields is inserted into the cf_user_question_link table)
Though now the trigger function works as expected but the issue that I faced was it because there were rows already in the cf_question table before the trigger function was deployed ?
regards
Kiran