Per-app machineTypesFilter broken in serverclass.conf

I have a server class defined in serverclass.conf and I want to install a different app based on the machineTypesFilter.

[global]
repositoryLocation = $SPLUNK_HOME/etc/deployment-apps
targetRepositoryLocation = $SPLUNK_HOME/etc/apps
stateOnClient = enabled
restartSplunkd = true
whitelist.0 = *

[serverClass:SomeClass]
whitelist.0 = *
[serverClass:SomeClass:app:WindowsApp]
machineTypesFilter = windows-x64
[serverClass:SomeClass:app:LinuxApp]
machineTypesFilter = linux-x86_64

However the machineTypesFilter seems to be broken and no apps are deployed.

This is basically a copy of Example 3 in the serverclass.conf documentation.