Every interval gets reset to 1d upon studying since upgrading Anki

I recently upgraded from Anki 2.1.35 to 2.1.49 running on Arch Linux. I am not using any addons.

As soon as I did that, every card gets reset to an interval of 1 day as soon as I study it, regardless of the previous state of the card. “1d” is shown as the interval for all rating options, even for the “again” button, which is really strange.

I know not how it happened, but it turned out that the “maximum interval” setting in my deck options was set to 1d, rather than the default of 36500d.