Last learning step and Graduating interval relation

Hey there, I recently changed my deck settings to 25 1440, with a graduating interval of 1d. Previously I had more steps after the 1440 one.
I did this cause I like having a 12h hard button interval that I can use a sort of “fast bury button”. (using 2.1 scheduler)
I thought/remembered this would result in a new card graduating with my last learning step, i.e. the very next day after pressing “good”.
What I’m experiencing is different though, with the card being shown the next day as a still-in-learning card. If I press good again, I’ll review it next day, this time as a graduated card.
So in the end I have 2x 1d intervals, vs 1x 1d, that I expected.
Did I recall wrong, and it has always been like that?

If “graduating interval” is set to an interval equal/lower to last learning step, what should happen?

When I try setting 1440 as the only learning step, and keeping 1d as grad ivl, after answering good once the card is marked as a review one.
Changing to 25 1440, answering good doesn’t change card’s learning status.
I really can’t figure out the difference in those 2 settings.

So you’ve set the steps to 25 1440 and the graduating interval to 1.
When a new card is shown to you you rate the first step and it becomes a learning card. If you rate “Good” that means the card has pased this learning step (“25”) and will be shown after the next step’s interval (1440 minutes) has passed.* If you rate “Good” again, the card has passed it’s last learning step and is said to have graduated. It is now a review card and is assigned the graduating interval of 1 day.
I hope that clears everything up. In general, you’ll want to set the graduating interval higher than the last learning step.

* Actually, that’s as soon as your day threshold is passed, so exactly like a review interval of 1 day.