Figure with flexbox not rendered correctly when footnotes exist

[MurakamiShinyu]

Test case: (GitHub Gist)
https://gist.github.com/MurakamiShinyu/c2c5aea0e8eeabe1d4d14e6d7a213e15

In this test, the figure and its style are specified as below:

    <figure>
      <img src="https://upload.wikimedia.org/wikipedia/commons/9/93/Cornelis_Cornelisz._van_Haarlem_002.jpg" alt="">
      <figcaption>オリュンポス神とティーターノマキアー</figcaption>
    </figure>

figure {
  align-items: center;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  max-height: 100%;
}

Test with Vivliostyle Viewer v2.30.1:
https://vivliostyle.github.io/viewer/v2.30.1/#src=https://gist.githubusercontent.com/MurakamiShinyu/c2c5aea0e8eeabe1d4d14e6d7a213e15/raw/figure-test.html

Screenshot (pages 2-3):

When figure { width: 100%; } is specified, this problem does not happen: