What is your “desired retention” setting, and did you change it since these cards were last reviewed?
Based on the stability and intervals you showed, it looks like maybe you currently have a high (over 90%) desired retention, which is making your intervals shorter.
Between those early-July reviews and now, you’ve upgraded Anki (possibly multiple times), switched from FSRS-5 to FSRS-6, and optimized your parameters a half-dozen times (weekly re-optimization is more often than necessary, and probably why your D values are jumping around so much in your review history). FSRS relies on your parameters, your DR, and the card’s memory state when scheduling – not on the card’s prior interval.
I don’t think you can expect that your new interval will always be longer than the last interval when you’re so frequently changing the things that FSRS relies on.
Hello hnvy,
I’m in the same situation as you. I update Anki whenever there’s an update, and I optimize the parameters once a month. I also have many cards where, in the last review, the interval became shorter and the difficulty increased. As Danika_Dakika said, I think this is normal and mainly due to the transition from FSRS-5 to FSRS-6. Let’s keep observing how these cards behave over the next few months.
