When a new card is created, a seemingly arbitrary deck is preselected, which almost always (if one has enough decks) forces the user to select the appropriate deck.
The current preset criteria is actually mysterious - I though it was the one selected in the previous session, but it isn’t.
It’d be much more user-friendly/efficient, if the deck selected in the tree panel (if selected) was preset instead.
I’ve dug a bit, and the problem is that the “current” deck is always the one selected in the main window (Decks).
That selection is still applied when current window is Browse, which I think is a bug (instead, it should be the deck selected in the tree panel).
If you use “Create Copy” instead of clicking on “Add”, the new note will use current’s card deck by default.
But yes, I also think that most users would expect the same behavior after clicking on “Add” note, so adding “When adding default to current’s card deck” as an option would be great.
+1
I also find it confusing, so at this point I always hit Ctrl D to change the deck as soon as I enter the ‘Add’ screen
Thanks for the suggestion! I use the same workaround, indeed 
Open source and good UX have always been, and will always be, sworn enemies: issue #2341 (“Preference “When adding, default to current deck” has confusing (or maybe buggy) UX”) in the ankitects/anki GitHub repo has been closed as not an issue. 
