log4j2 does not log in webapplication deployed on tomcat - maven

Question

I am upgrading the version of log4j for a web application running on Tomcat 8. I am upgrading from version 1.2.12 to the latest 2.11.1.
The application is using Maven. So I added the following dependencies to my application pom.xml (version is managed in parent pom):
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
</dependency>
I removed the old configuration file log4j.properties and replaced it by a new log4j2.xml file in the folder src/main/resources (find below my log4j2 file content).
When I am running directly a main function, the logs are correctly written in console and in a file. However when I deploy the application on Tomcat, and run it, no log is written.
I checked my application WAR, and both libraries are present in WEB-INF/lib folder.
I also tested by adding exclusions to log4j-1** to external libraries that have dependency on it, but nothing changed...
Did someone already had the same issue, and how did you correct it?
Regards,
Matthieu
PS: content of my log4j2.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status=WARN strict="true">
<Properties>
<Property name="pattern">%d [%t] (%F:%L) %x %-5p [%c{1}] %m%n</Property>
<Property name="filePath">C:/temp/logs/my_app/my_app.log</Property>
</Properties>
<Appenders>
<Appender type="Console" name="STDOUT">
<Layout type="PatternLayout" pattern="${pattern}"/>
</Appender>
<Appender type="RollingFile" name="FILE" fileName="${filePath}" filePattern="${filePath}.%i">
<Layout type="PatternLayout" pattern="${pattern}"/>
<Policies>
<SizeBasedTriggeringPolicy size="500KB"/>
</Policies>
<DefaultRolloverStrategy max="1"/>
</Appender>
</Appenders>
<Loggers>
<Logger name="my.package.debug" level="DEBUG" additivity="false">
<AppenderRef ref="STDOUT"/>
<AppenderRef ref="FILE"/>
</Logger>
<Root level="WARN">
<AppenderRef ref="STDOUT"/>
<AppenderRef ref="FILE"/>
</Root>
</Loggers>
</Configuration>

Answer 1

I finally found my issue, it was due to another library (infinispan-embeded) which was redefining Log4j classes, such as LogManager. I was loading thoses classes instead of those in log4j libraries, and they was in older version than what I wanted.
I just replaced the library, and logs are correctly written in file.