napari: Pyside 5.15.0 breaking buttons?

from qtpy.QtCore import Qt
from qtpy.QtWidgets import (
    QWidget,
    QApplication,
    QPushButton,
    QMainWindow,
    QHBoxLayout,
    QVBoxLayout,
    QFrame,
    QSplitter,
    QDockWidget,
)


class QtViewerPushButton(QPushButton):
    def __init__(self, button_name, slot=None):
        super().__init__(button_name)
        if slot is not None:
            self.clicked.connect(slot)


class QtLayerButtons(QFrame):
    def __init__(self):
        super().__init__()
        self.newPointsButton = QtViewerPushButton("new_points", lambda: print("click"))
        layout = QHBoxLayout()
        layout.addWidget(self.newPointsButton)
        self.setLayout(layout)


class QtViewerDockWidget(QDockWidget):
    def __init__(self, qt_viewer, widget: QWidget, name: str = ""):
        self.qt_viewer = qt_viewer
        super().__init__(name)
        self.qt_area = Qt.LeftDockWidgetArea
        self.setMinimumHeight(50)
        self.setMinimumWidth(50)
        self.setWidget(widget)
        widget.setParent(self)
        self._widget = widget


class QtViewer(QSplitter):
    def __init__(self, viewer):
        super().__init__()

        self.viewer = viewer
        self.layerButtons = QtLayerButtons()
        layerList = QWidget()
        layerListLayout = QVBoxLayout()
        layerListLayout.addWidget(self.layerButtons)
        layerList.setLayout(layerListLayout)
        self.dockLayerList = QtViewerDockWidget(self, layerList, name="layer list")
        self.dockLayerList.setMaximumWidth(258)
        self.dockLayerList.setMinimumWidth(258)


class Window:
    def __init__(self, qt_viewer: QtViewer, *, show: bool = True):
        self.qt_viewer = qt_viewer
        self._qt_window = QMainWindow()
        self._qt_center = QWidget(self._qt_window)
        self._qt_center.setLayout(QHBoxLayout())
        self._qt_center.layout().addWidget(self.qt_viewer)
        self._qt_center.layout().addWidget(
            QtViewerPushButton("asdf", slot=lambda: print("click"))
        )
        self._qt_window.setCentralWidget(self._qt_center)
        self._qt_window.setFixedSize(500, 300)
        self._add_viewer_dock_widget(self.qt_viewer.dockLayerList)

        if show:
            self._qt_window.resize(self._qt_window.layout().sizeHint())
            self._qt_window.show()

    def _add_viewer_dock_widget(self, dock_widget: QtViewerDockWidget):
        """Add a QtViewerDockWidget to the main window

        Parameters
        ----------
        dock_widget : QtViewerDockWidget
            `dock_widget` will be added to the main window.
        """
        dock_widget.setParent(self._qt_window)
        self._qt_window.addDockWidget(dock_widget.qt_area, dock_widget)


class Viewer:
    def __init__(self):
        qt_viewer = QtViewer(self)
        self.window = Window(qt_viewer, show=True)


app = QApplication([])
v = Viewer()
app.exec_()