Quarkus Class Loader Problem

Loading class java.lang.reflect.ParameterizedType in the wrong classloader instance of io.quarkus.bootstrap.classloading.QuarkusClassLoader(id=8998)

Maven dev mode, also prod mode

IntelliJ, Maven 3.9.8, Quarkus 3.12.1,OpenJDK 17

I want to do a SOAP Webservice-Call using our own written Webservice-Stack

Code that causes problem:

this.hasWebServiceAnnotation((ParameterizedType)clazz.getGenericSuperclass())
error: Loading class java.lang.reflect.ParameterizedType in the wrong classloader instance of io.quarkus.bootstrap.classloading.QuarkusClassLoader(id=8998)

method

protected Class<WS_INTERFACE_TYPE> findPortTypeInterface(Class<?> clazz) {
    Class<WS_INTERFACE_TYPE> portType = null;
    if (clazz.getSuperclass() != null) {
        if (clazz.getGenericSuperclass() instanceof ParameterizedType && this.hasWebServiceAnnotation((ParameterizedType)clazz.getGenericSuperclass())) {
            portType = (Class)((ParameterizedType)clazz.getGenericSuperclass()).getActualTypeArguments()[0];
        } else {
            portType = this.findPortTypeInterface(clazz.getSuperclass());
        }
    }
    return portType;

Above class / method (from own written Webservice-Stack) is included by pom dependency

I tried some hints from following but didn’t help
https://quarkus.io/guides/class-loading-reference