It isn’t working how I expected. Because (referring to the original screenshot) it is also giving me cards that are ready to “Learn”, which I believe isn’t the same as New?
EDIT:
Another thing that confuses me is that some of the cards now appear to belong to the new filtered deck… e.g., if I navigate to one of the cards in the browser window (for the original JLPT Tango N5 deck), and I go Cards->Info, I can see it associated with the filtered deck instead:
When you build that deck, it will only take New cards, but as soon as you introduce and grade a card in the Filtered Deck, it becomes a Learn card – just like in a standard deck. Since you have reschedule-based-on turned on, the cards will finish Learn here (based on the learning steps in the home deck), and return to their home deck once they graduate to Review – Filtered Decks - Anki Manual . If you want to kick those Learn cards back to their home deck sooner, you can Rebuild the deck.
Cards can only be in one deck at a time, so when cards are in a Filtered Deck, they can’t be studied from their home deck. A Filtered Deck is special, because it allows cards to remember where they came from, but if you want them to be accessible from their home deck, you have to Empty the deck.
[advice you didn’t ask for]
If you want to Learn a chunk of New cards, there are easier ways to do this. For instance, you can set your home decks to a reasonable number of New cards, and set the Deck Options to have New cards come before Review cards – https://docs.ankiweb.net/deck-options.html#newreview-priority.
When you have 50+ cards in Learn (I’m looking at your N5 deck), you probably shouldn’t be trying to find ways to introduce more New cards. Now you have 100+ that you need to Learn and graduate to Review today.