I think you meant 1 year mark on 1 Dec 2019? and 3 year mark on 1 Dec 2021?no, the gap won’t be an issue.
I got my ITA with 35 months of work experience because the resolution by which work experience is calculated is in months, not weeks or days. So if for example, you started working on 25 Jan 2018, your work experience would be considered as having reached its 1 year mark on 1 Dec 2018, and 3 year mark on 1 Dec 2020, and not 25 Jan 2019 or 2021 respectively.
And so didn't the visa officer ask any questions or like just saying if I updated my profile right now and since I have completed 35 months (36 months via the month calculation rule) - I would not face any issues if I get an ITA in the next FSW draw?
Thanks for your response , grateful.