11.1.0 regression: FontFamily="Monospace" doesn't do anything

[AnErrupTion]

Describe the bug

On 11.1.0-beta2, setting FontFamily="Monospace" anywhere (it can be in the global Window or an individual component) produces no visual effect, whereas it works on 11.0.10.

To Reproduce

1. Create a new Avalonia .NET App project
2. Upgrade the dependencies to 11.1.0-beta2
3. In MainWindow.axaml, add FontFamily="Monospace" to the Window tag

Expected behavior

I expect the font to change to the system's monospace font (see screenshots below).

Avalonia version

11.1.0-beta2

OS

Linux

Additional context

11.1.0-beta2:

11.0.10: