Everyone makes mistakes some correct them some d ont realise until co ask for clarification, i found 2 missing info and 2 incorrect answers so far in my form 80 and spouses form all related to employment and unemployment dates, there is an option to update incorrect answers in immi account , i think on left side under update us, You just have to select the applicants name the incorrect answer relates to, then in details box include form number eg. Form 80 - Question 19 part F etc. , then it asks for what incorrect answers you provided ( copy paste the incorrect answer here or write brief explanation) , next box asks for correct answer so include correct answer , then next one asks why you provided incorrect answers i simply used overlooked missing information or forgot to enter or overlooked the incorrect answer as explanation. follow the procedure from beginning for each incorrect/missing answer and at the end make sure you press submit.