Hi SweetNana, last week of 2019 and the first week of 2020 share the same week. I informed Scott about this. If you manually change the leaderboard address bar from 01-2020 to 52-2019 all images submitted this week will show.
Jasenka, images from December 29, 30, and 31 of 2019 still do not show up on the leaderboard for any week in the Illustration and Design category. They should be up for "this week" even though they have a 2019 date. In the typography category, it affects 26 images. I just retried that week 53 trick and it still only brings back the Jan. 1 through current images of 2020. I sure hope this glitch gets fixed before the weekly awards are given for this week.