QML Singleton does not get instanciated when root .qml file is in the same subfolder

pragma Singleton
import QtQuick

QtObject
 {
    readonly property int foo: 250
    Component.onCompleted: {
        console.log("hi from singleton")
    }
}

import QtQuick
Window {
    visible: true
    Component.onCompleted: console.log(Style.foo)
}

cmake_minimum_required(VERSION 3.16)

project(singleton-bug VERSION 0.1 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 6.5 REQUIRED COMPONENTS Quick)

qt_standard_project_setup(REQUIRES 6.5)

set_source_files_properties(qml/Style.qml PROPERTIES
    QT_QML_SINGLETON_TYPE TRUE
)
qt_add_executable(appsingleton-bug
    main.cpp
)

qt_add_qml_module(appsingleton-bug
    URI singleton-bug
    VERSION 1.0
    QML_FILES
        # Main.qml  # OK
        qml/Main.qml # Buggy
        qml/Style.qml
)

target_link_libraries(appsingleton-bug
    PRIVATE Qt6::Quick
)