Try asking the jam organizers directly, in the jam's own community, they can approve your game manually, and/or extend the deadline. Or at least check and tell you exactly what happened. Hope this helps!
Viewing post in Game Jam Issues
I'm new to itch.io and therefore I dont know where the "jam's own community" is. If you're referring to https://itch.io/jam/friday-night-game-jam-2020-45 which is the page with all the submissions and rules, etc then I've already looked and couldn't find any way to contact anyone. I guess at this point its far to late to have my work be part of the jam but at this point it would be nice to know where to look. Thanks