how to have a standalone groovy script with logback logging output - linux

Question

I wrote a groovy script which uses {{org.slf4j.Logger}} and Logback to give output to a file and the console. When running this script within my development environment (project, maven, etc.) it works fine.
When I export my script to my linux machine and execute it there - nothing happens. The script actually runs - but not output to stout or a file.
I then tried to have one {{println}} statement within my script and retried executing the script on the linux machine. The statement string was brought to the stout.
So the issue here is that my script does not log anything outside the development environment.
How can I get my script to work with the logging as standalone script?
logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<appender name="file" class="ch.qos.logback.core.FileAppender">
<file>script.log</file>
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<logger name="com.application" additivity="false" level="warn">
<!--<appender-ref ref="file"/>-->
<appender-ref ref="stdout"/>
</logger>
<logger name="hox" additivity="false" level="warn">
<!--<appender-ref ref="file"/>-->
<appender-ref ref="stdout"/>
</logger>
<!-- Debug logging: override via JVM-Option, eg. -->
<!-- -Droot.log.level=DEBUG -->
<root level="${root.log.level:-DEBUG}">
<appender-ref ref="file"/>
<appender-ref ref="stdout"/>
</root>
</configuration>