QMenuBar QMenu is too short when first clicked

Question

I'm running into a strange one here. I have a QMenuBar attached to a QMainWindow with multiple QMenus and QActions contained in it. When the program is first started, and one of the menus is clicked, the resulting drop-down is too short. But if the menu is opened a second time, it's just fine, and looks as expected as the program continues to be used. But, if the program is restarted, the first click on the menu results in a too-short drop-down again.

First click:

Subsequent clicks:

This occurs on all of the menus (File, Edit, Record, and Help). Anyone run into this before and know why this is happening?

Here's some of the pertinent code:

The QMainWindow:

class Win(QMainWindow):
    from PySide6.QtGui import QCloseEvent
    gui = None
    def __init__(self, gui):
        QMainWindow.__init__(self)
        self.gui = gui
        self.setWindowTitle('Sermon Prep Database')
        self.setStyleSheet('background-color: white')
        self.resize(1000, 800)

    def closeEvent(self, event:QCloseEvent) -> None:
        event.ignore()
        self.gui.doExit()

    def keyPressEvent(self, event:QKeyEvent):
        if event..modifiers() & Qt.ControlModifier and event.key() == Qt.Key_B:
            self.gui.setBold()
        ..lotsa different handlers...
        event.accept()

Then, from GUI(), the Menubar is created like this:

def buildMenuBar(self):
    menubar = self.win.menuBar() #win is the instance of the Win() class
    menubar.setStyleSheet('QMenuBar::item:selected { background: WhiteSmoke; }')

    filemenu = menubar.addMenu('File')
    filemenu.setStyleSheet('QMenu::item:selected { background: WhiteSmoke; color: black}')

    saveaction = filemenu.addAction('Save (Ctrl-S)')
    saveaction.triggered.connect(self.spd.saveRec)

    printaction = filemenu.addAction('Print (Ctrl-P)')
    printaction.setStatusTip('Print the current record')
    printaction.triggered.connect(self.printRec)

    backupaction = filemenu.addAction('Create Backup')
    backupaction.setStatusTip('Manually save a backup of your database')
    backupaction.triggered.connect(self.dobackup)

    filemenu.addSeparator()

    exitaction = filemenu.addAction('Exit (Ctrl-Q)')
    exitaction.setStatusTip('Quit the program')
    exitaction.triggered.connect(self.doExit)
    ... and more items...

This is in Windows 11, by the way. I haven't tried it on any other platforms.

Edit: Here is a minimum reproduceable example that shows the same behavior: impor

import sys
from PySide6.QtWidgets import QApplication, QBoxLayout, QWidget, QMainWindow

class SermonPrepDatabase:
    gui = None

    def __init__(self):
        self.startup()

    def startup(self):
        self.app = QApplication(sys.argv)
        self.gui = GUI(self)
        self.gui.initComponents()
        self.gui.win.show()

        sys.exit(self.app.exec())

class GUI():
    accentColor = '#202050'
    backgroundColor = '#f0f0ff'
    spd = None
    win = None

    def __init__(self, spd):
        self.spd = spd

    def initComponents(self):
        self.win = Win(self)

        self.layout = QBoxLayout(QBoxLayout.TopToBottom)
        self.mainwidget = QWidget()
        self.mainwidget.setStyleSheet('background-color: ' + self.backgroundColor + ';')
        self.win.setCentralWidget(self.mainwidget)
        self.mainwidget.setLayout(self.layout)

        self.buildMenuBar()

    def buildMenuBar(self):
        menubar = self.win.menuBar()
        menubar.setStyleSheet('QMenuBar::item:selected { background: WhiteSmoke; }')

        filemenu = menubar.addMenu('File')
        filemenu.setStyleSheet('QMenu::item:selected { background: WhiteSmoke; color: black; }')

        saveaction = filemenu.addAction('Save (Ctrl-S)')
        saveaction.triggered.connect(self.afunction)

        printaction = filemenu.addAction('Print (Ctrl-P)')
        printaction.setStatusTip('Print the current record')
        printaction.triggered.connect(self.afunction)

        backupaction = filemenu.addAction('Create Backup')
        backupaction.setStatusTip('Manually save a backup of your database')
        backupaction.triggered.connect(self.afunction)

        filemenu.addSeparator()

        exitaction = filemenu.addAction('Exit (Ctrl-Q)')
        exitaction.setStatusTip('Quit the program')
        exitaction.triggered.connect(self.afunction)

        editmenu = menubar.addMenu('Edit')
        editmenu.setStyleSheet('QMenu::item:selected { background: WhiteSmoke; color: black}')

        cutaction = editmenu.addAction('Cut (Ctrl-X)')
        cutaction.triggered.connect(self.afunction)

        copyaction = editmenu.addAction('Copy (Ctrl-C)')
        copyaction.triggered.connect(self.afunction)

        pasteaction = editmenu.addAction('Paste (Ctrl-V)')
        pasteaction.triggered.connect(self.afunction)

        configmenu = editmenu.addMenu('Configure')

        bgColorAction = configmenu.addAction('Change Accent Color')
        bgColorAction.setStatusTip('Choose a different color for accents and borders')
        bgColorAction.triggered.connect(self.afunction)

        fgColorAction = configmenu.addAction('Change Background Color')
        fgColorAction.setStatusTip('Choose a different color for the background')
        fgColorAction.triggered.connect(self.afunction)

        renameAction = configmenu.addAction('Rename Labels')
        renameAction.setStatusTip('Rename the labels in this program')
        renameAction.triggered.connect(self.afunction)

        fontaction = configmenu.addAction('Change Font')
        fontaction.setStatusTip(('Change the font and font size used in the program'))
        fontaction.triggered.connect(self.afunction)

        recordmenu = menubar.addMenu('Record')
        recordmenu.setStyleSheet('QMenu::item:selected { background: WhiteSmoke; color: black}')

        firstrecaction = recordmenu.addAction('Jump to First Record')
        firstrecaction.triggered.connect(self.afunction)

        prevrecaction = recordmenu.addAction('Go to Previous Record')
        prevrecaction.triggered.connect(self.afunction)

        nextrecaction = recordmenu.addAction('Go to Next Record')
        nextrecaction.triggered.connect(self.afunction)

        lastrecaction = recordmenu.addAction('Jump to Last Record')
        lastrecaction.triggered.connect(self.afunction)

        recordmenu.addSeparator()

        newrecaction = recordmenu.addAction('Create New Record')
        newrecaction.triggered.connect(self.afunction)

        delrecaction = recordmenu.addAction('Delete Current Record')
        delrecaction.triggered.connect(self.afunction)

    def afunction(self):
        pass

class Win(QMainWindow):
    from PySide6.QtGui import QCloseEvent
    gui = None
    def __init__(self, gui):
        QMainWindow.__init__(self)
        self.gui = gui
        self.setWindowTitle('Sermon Prep Database')
        self.setStyleSheet('background-color: white')
        self.move(50, 50)
        self.resize(1000, 800)

    def closeEvent(self, event:QCloseEvent) -> None:
        event.ignore()
        self.doExit()

    def doExit(self):
        sys.exit(0)

SermonPrepDatabase()