java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter even if the configuration looks fine

I'm aware that there are plenty of similar questions on StackOverflow, but I guess I went through each of them and tried all the suggested ones, but none of them worked.

I am trying to migrate an application from struts 1 to struts 2, but for makes things easier I'm trying first to migrate the struts1 sample applications in order to get confident with the steps. The sample applications I'm talking about are the ones in the apps folder of this repository.

So, this is my current configuration:

• maven
• Java 8
• Tomcat 9
• Struts 1.4
• Struts 2.5

The steps that I've done so far have been:

1. Add struts2-core and log4j2 dependencies in the pom.xml file, and install them through maven
2. Change the web.xml file to include struts 2, according to official documentation.
3. Create a struts.xml file in the classpath, currently that file doesn't contain any action but just the structure.

The above-mentioned files look like this:

web.xml (excerpt):

 <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
 </filter>
 <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
 </filter-mapping>

 <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>*.action</url-pattern>
 </filter-mapping>

struts.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
        "http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
    <constant name="struts.enable.DynamicMethodInvocation" value="false"/>
    <constant name="struts.devMode" value="true"/>

    <package name="default" namespace="/" extends="struts-default">

    </package>

    <!-- Add addition packages and configuration here. -->
</struts>

pom.xml (excerpt):

   <dependency>
       <groupId>org.apache.struts</groupId>
       <artifactId>struts2-core</artifactId>
       <version>2.5.22</version>
       <scope>compile</scope>
   </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.12.1</version>
    </dependency>

In the end, the maven dependencies section looks like this:

While the WEB-INF/lib folder in the target folder looks like this:

So I'm sure that all the required dependencies are present in the target. Despite this, I keep getting the error:

org.apache.catalina.core.StandardContext filterStart SEVERE: Exception starting filter [struts2] java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter

I'm sure that the class org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter exists, it's spelled correctly and it's correct for the version of struts2 that I'm using, since if I import the class in a Java file, it gets built succesfully.

I know that the problem is very common and my request can sound stupid, but I've checked literally any question that I found on the web about this problem and none of the solutions worked.

I hope that someone could give me a hint. Thank you