Strange card scheduling that doesn't match FSRS stability?

I am seeing a strange behavior with some cards where they seem to get scheduled for intervals longer than their FSRS stability would suggest is appropriate.

Here is an example for a card that has always been on FSRS (so no SM-2 → FSRS conversion weirdness happening):

The card came up for study roughly 30 minutes after I last saw it. Before answering, it had an FSRS stability of 2.1 hours and difficulty of 98%. I answered “Good”, and after answering the card had an FSRS stability of 3 hours and a difficulty of 98%, but for some reason it was scheduled for an interval of 1 day.

I am currently more than 12 hours from my Anki “day starts at” time, so this shouldn’t be a day boundary thing.

Here’s what shows in the card info after the last answer:

Date				Type	Rating	Interval	Ease	Time
2026-05-28 @ 17:55	Relearn		3	1 day		D:98%	10s
2026-05-28 @ 17:21	Relearn		2	15 minutes	D:98%	9.01s
2026-05-28 @ 17:04	Review		1	10 minutes	D:97%	4.04s
2026-05-26 @ 20:33	Review		3	2 days		D:91%	3.1s
2026-05-26 @ 01:43	Learn		3	1 day		D:91%	10s
2026-05-26 @ 01:33	Learn		2	10 minutes	D:91%	5.35s
2026-05-26 @ 01:18	Learn		3	10 minutes	D:87%	2.12s
2026-05-26 @ 01:16	Learn		1	1 minute	D:87%	2.96s
2026-05-26 @ 01:15	Learn		1	1 minute	D:60%	9.54s

My current settings/details:

  • Desired retention 95%
  • Learning steps “1m 10m” (the default)
  • Relearning steps “10m” (the default)
  • FSRS parameters (after optimizing): “0.0173, 1.3935, 2.6229, 4.4955, 6.4183, 0.8287, 3.0259, 0.0010, 1.8404, 0.1527, 0.7620, 1.4849, 0.0664, 0.2712, 1.6517, 0.5835, 1.8729, 0.4758, 0.1400, 0.1049, 0.1000”
  • Anki desktop version 25.09.2. (On MacOS in this case, but pretty sure I’ve seen the same thing on Linux too.)

I can see that the card had type “Relearn” twice, since the first review where I pressed “Hard” didn’t let it out of relearning.

Why would this card get a 1-day interval when FSRS says its stability is too low for that?

(I’m more than 12 hours from my Anki “day starts at” time, I have triple-checked that I only have one 10-minute relearning step, and I do not have any addons that would do anything to card scheduling.)

The card is graduating to Review and 1d is the minimum interval for Review-card scheduling.