It’s not completely clear what you’re showing us. These are pairs of sibling cards, but we’re missing some important parts of the revlog (times, stages, etc.), because your screen is narrow. [We’d need these screenshots in landscape mode to see everything.]
Maybe a better place to start would be you describing what your settings were when you started the day, what you studied, what happened, and what you expected to happen differently.
Non-bug explanations for this include –
The cards were studied on different “study”-days, even if they were the same date – because of where the day boundary is.
The buried siblings were unburied by some other action, and available to be studied.
Day boundary is at 00:00 so this can be ruled out.
I’m using AnkiDroid as-is so add-ons can be ruled out. I didn’t unbury them myself, and am not aware of other possibilities. (ETA: neither deck is a filtered deck.)
If I understood the manual correctly, the card later in queue, regardless of its stage, should be buried if all “bury” options are enabled. All those options are enabled in all of my presets. For the same reason, I thought the original screenshots were enough. No matter where it’s at, new, review, or learning, it should be buried. But I can understand this information is needed to narrow down the problem:
The logs on both examples show that none of them is a backlog card, if it matters at all. In Example 1 Anki showed both the Reverse and Forward cards on 2026-01-06, and in Example 2 both on 2026-01-05. All the bury options in presets were enabled before those dates, and I can confirm that intra-deck burying has been working well.