ModuleNotFoundException after Thorntail upgrade

Question

I just upgraded the Thorntail version of my application from 2.5.0.Final to 2.6.0. Final. My app is using a module (for authorization), which lies in a separate git repo, so I've included it in my pom.xml.

Since the upgrade I'm getting a ModuleNotFoundException when the module is called (authorization is triggered)

Caused by: org.jboss.modules.ModuleNotFoundException: org.apache.santuario.xmlsec
at org.jboss.modules.Module.addPaths(Module.java:1266) [backend-thorntail.jar:]
at org.jboss.modules.Module.link(Module.java:1622) [backend-thorntail.jar:]
at org.jboss.modules.Module.relinkIfNecessary(Module.java:1650) [backend-thorntail.jar:]
at org.jboss.modules.ModuleLoader.loadModule(ModuleLoader.java:299) [backend-thorntail.jar:]
at org.jboss.modules.ModuleLoader.loadModule(ModuleLoader.java:283) [backend-thorntail.jar:]
at org.jboss.as.security.plugins.SecurityActions.getModuleClassLoader(SecurityActions.java:50) [thorntailwildfly-security-18.0.1.Final5333088777079625058.jar:18.0.1.Final]
at org.jboss.as.security.plugins.ModuleClassLoaderLocator.get(ModuleClassLoaderLocator.java:65) [thorntailwildfly-security-18.0.1.Final5333088777079625058.jar:18.0.1.Final]
... 49 more

The problem is, that the org.apache.santuario.xmlsec dependency of the module is not being bundled in the thorntail jar, while all other dependencies are present in the jar.

This is the module.xml of the used module:

</module>
    ...
    <dependencies>
        <module name="javax.api"/>
        <module name="javax.servlet.api"/>
        <module name="org.apache.xalan"/>
        <module name="org.apache.santuario.xmlsec"/>
        <module name="org.picketbox"/>
        <module name="org.jboss.logging"/>
    </dependencies>
</module>

Does anyone have an idea how I can "force" Thorntail to include this dependency? I also tried simply adding the latest version of the missing dependency in my pom.xml but unfortunately this doesn't help.

Any help is appreciated - thanks!