I'm having the same problem. It's showing me a list of games I've made but the game I made for the jam is not showing. It's showing as published and I can access it from a private window but can't select it on the submit page.
Have you tried refreshing the page after the game was published?
Yeah I've refreshed the page and I even tried logging in through a private page and it still won't let me submit.
But in the "Jams you've submitted to" page this game jam shows up.
If you go to your game through your page it will say on the top right if it is submitted to the jam
