Displays saves "invalid" scale to displays.xml

When using Displays to apply fractional scaling, the displays.xml configuration file stored in ~/.config/xfce4/xfconf/xfce-perchannel-xml on my machine is saved with the following additional xml snippet. It appears to be causing a problem.

<property name="Scale" type="empty">
  <property name="X" type="double" value="0.699997"/>
  <property name="Y" type="double" value="0.699997"/>
</property>

Upon rebooting my machine, when I log in using lightdm, the desktop never appears and the screen remains black.
After I manually change the snippet to the below, the desktop loads properly scaled.

<property name="Scale" type="empty">
  <property name="X" type="double" value="0.7"/>
  <property name="Y" type="double" value="0.7"/>
</property>

The following also works:

<property name="Scale" type="empty">
  <property name="X" type="double" value="0.700000"/>
  <property name="Y" type="double" value="0.700000"/>
</property>

Arch Linux x86_64
20HHCT01WW ThinkPad P51
5.9.14-arch1-1
Xfce 4.16
zsh 5.8