Can you link to the game page so we can take a closer look? Generally a file lock for game jams only happens when the jam has a rating period in progress (the jam is not over). Once rating has ended you can edit files freely. You can, however, delete files when there’s a file lock in progress.
If you need to make adjustments to your submission you’ll have to remove your page from the jam, make the changes, then ask the jam host to generate a late submit link for you.
(I edited your topic title to be more descriptive of the issue)