I’m using Anki Desktop 2.1.30 (06a69c25) on Windows 10.
With the 2.1 beta scheduler, when reviewing a parent deck with a maximum review count N, the scheduler does not respect a subdeck’s maximum review count M < N.
I have created an example collection that reproduces the bug. I couldn’t attach it here, but it can be downloaded from http://firstname.lastname@example.org for the time being.
The collection has a parent deck with a high max reviews/day limit and a subdeck with a limit of 3 reviews/day. The subdeck has 6 reviews due. The 2.1 beta scheduler is enabled. When reviewing the parent deck, the interface shows that there are 3 cards to review. However, Anki ends up showing all 6 cards and the due count goes negative.
I have not verified whether a similar bug exists for new cards.
Many thanks for your continuous efforts to maintain and improve Anki!