[Help Please] Can find completed decks in browse, but deck appears empty on main screen

I recently studied through 3 sub-decks, within a much larger deck. I “completed” each of these decks, with no cards left to review.

After finishing, both on mobile, my Mac, and on AnkiWeb, these 3 sub-decks appear to no longer have any cards in them.

I have checked, and they are not just stashed randomly in the larger deck.

Any ideas? I have tried synching, restarting the app on both mobile and on my Mac.

Included a few screenshots to try and help in diagnostics.

(pls help - i have an important exam in 2 days :frowning: )

Screen Shot 2021-09-26 at 10.51.08 PM

Update - here is a screenshot of what just happened when I tried to synchronize on Anki Mobile.

That’s normal: Anki's not showing me all my cards! - Frequently Asked Questions
In your first screenshot, you can see that some cards are going to be due on September 27th and 28th. I don’t know your time zone, but I assume you’ve posted on the 26th, and some cards have appeared in the meantime.
If you want to cram before your exam, you can use a filtered deck: Filtered Decks - Anki Manual

Since there is no indication that anything is wrong with your scheduling, the error appears to be unrelated. Try using the Check Database function.