OpenType font features do not display on any element that shares all font properties with an element that has a property set using the ch unit.

The incorrect behaviour is observed on:

Firefox 134.0.2 on Linux
Firefox 135.0 on Windows
Firefox 133.0 on Android
Firefox 135.0.1 on Android

The correct behaviour is observed on:

Firefox 135.0 on macOS 15.1
Chromium 133.0.6943.54 on macOS 15.1
Chromium 132.0.6834.159 on Linux
Edge 132.0.2957.140 on Windows
Vivaldi 7.1.3570.47 on Windows
Vivaldi 7.1.3580.99 on Android
Safari 18.1 (20619.2.8.11.10) on macOS 15.1

EB Garamond

The first div has a font-size of 7rem and a height of 10rem. The elongated "Q" displays correctly.

The second div has a font-size of 8rem and a height of 3ch. The elongated "Q" does not display, because of the use of the ch unit.

The third div has a font-size of 8rem and a height of 10rem. The elongated "Q" still does not display, because of the use of the ch unit in the second div, which has the same font-size.

Queen

Open Sans

As for the other font.

going