Unable to use opentype style set with UnifrakturMaguntia

I want to use Stylistic Set 1 (ss01) of Unifraktur Maguntia to enable more modern forms of the blackletter font, but following directions for enabling it in LibreOffice has no effect. Even after entering “UnifrakturMaguntia:ss01=1” in the font field, it still has the default forms.

Version info:
Version: 5.1.3.2 (x64)
Build ID: 644e4637d1d8544fd9f56425bd6cec110e49301b
CPU Threads: 2; OS Version: Windows 6.19; UI Render: GL;
Locale: en-US (en_US)

Font info:
http://unifraktur.sourceforge.net/