Timer executed delayed if BPMS is configured to use Quartz

Issue

We are using a BPM process which contains a timer associated at a Human Task. The due date of the timer is set to 5 seconds.

After we changed our configuration to use Quartz, we noticed that the timer is executed with delay. Sometimes a few seconds, but sometimes it is only triggered after 25 seconds. We are referencing the quartz properties in standalone.xml and use the values from the BPMS configuration:

    <property name="org.quartz.properties" value="${jboss.server.config.dir}/quartz-definition.properties"/>

When using timer values above 30 seconds, the timer execution works correctly.