I’m not really sure if this is a bug or if it’s somehow intended, but here goes:
When I’m reviewing my cards on Anki Desktop, I sometimes do some maintenance or comparing with other cards on the fly, and doing this often makes Anki leave the card under review and jump to another card.
For instance, going to “Tools | Preferences” or “Tools | Manage Note Types” sets it off. As soon as I close the resulting window to return to review, the main Anki window jumps to another card.
I often encounter this when learning vocabulary: Sometimes there’ll be pairs of words that I regularly confuse, and so when one card of such a pair comes up for review, I’ll sometimes go to the card browser to check the other card and perhaps add information about confusion potential to better remember what sets them apart. And then when I close the card browser, the card under review disappears and is replaced by another card.
Is this supposed to happen? Because if it doesn’t serve any purpose in particular, it’d be nice if it would not do that 