Update: Got a request today, February 18th, 2021 to submit the following additonal document: IMM 5669. The request letter states that I have 7 days to submit this document and it should bear my original signature. Failure to meet the deadline can result in rejection as my application can be incomplete.
I checked, document IMM 5669 is the background decleration. It's asking me to fill exactly the same details I submitted in my initial online application, in the Questionnaire. Would anyone know why they would request this again?