<app_config>
<app>
<name>classical</name>
<max_concurrent>5</max_concurrent>
</app>
</app_config>

The reason for this app_config.xml is Leiden is another one of those annoying projects that likes to jump into high priority mode and eat up the cpu threads, which in turns stops gpu wus that have "higher" cpu requirements. This app_config stops classical from running more than 5 wus at a time, obviously you would change that number to fit your needs.