Extension not able to load project classes

[ErrorProne]

Maybe someone here can give me some pointers. I'm currently trying to write a test with vaadins testbench. The test is rather simple

@QuarkusTest
class ReportViewTest extends UIUnitTest {
	@Test
	void setText_clickButton_notificationIsShown() {
		final ReportView reportView = navigate(ReportView.class);
		assertThat(test(reportView.grid).size()).isEqualTo(0);
	}
}

However, vaadin fails miserably to load a class from my project:

java.lang.ClassNotFoundException: mytest.vaadinpoc.ReportView
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:489)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:466)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:375)
    at com.vaadin.testbench.unit.internal.Routes.autoDiscoverViews(Routes.kt:82)

The vaadin code tries to find all classes which are annotated with a special annotation and than load them:
Class.forName(info.name).asSubclass(Component::class.java)

While debugging it looks like the extension executing the code is loaded with a different classloader(?) instance which has all project files in the bannedElements list (

quarkus/independent-projects/bootstrap/core/src/main/java/io/quarkus/bootstrap/classloading/QuarkusClassLoader.java

Line 96 in b0cd886

private final List<ClassPathElement> bannedElements;

). Maybe for isolation purposes?
This however works at least in the debugger: ClassLoader.getSystemClassLoader().loadClass("mytest.vaadinpoc.ReportView")

Can anyone shed some light why this behaves like it does and maybe provide some pointers on what would be the right way to fix this?