While recently using the V3 scheduler, it stopped showing that there were new cards in every deck except one despite there being many new cards available in all decks. The options for the decks were adjusted multiple times to see if it would work with any different number of new cards/review cards limit, but nothing made the new cards appear. When V3 scheduler was disabled, these new cards showed again. The V3 scheduler had been working fine until today.
I recommend you to read this section of the documentation for the v3 scheduler and see if it applies to your case: Daily limits.