Electron window flashes white upon showing despite graceful display

I am trying to display a window with black content inside a BrowserWindow:

changeShortcutWindow = new BrowserWindow({
    height: 400,
    width: 600,
    show: false, // will be displayed upon ready-to-show
    resizable: false,
    maximizable: false,
    titleBarStyle: 'hidden', // make the content full-sized, while preserving native controls
    backgroundColor: "#000", // make the window background same as contentview background to avoid visual flash
    webPreferences: {
      preload: CHANGE_SHORTCUT_PRELOAD_WEBPACK_ENTRY,
    }
  });

changeShortcutWindow.loadURL(CHANGE_SHORTCUT_WEBPACK_ENTRY);

However upon loading the local URL, the window flashes white (completely empty, for one frame, I checked a screen recording) before it displays the full black content:

Based on the documentation you are supposed to wait for ready-to-show event but I am doing that. I am also setting the background color of the window to black (as seen above) and that doesn't help either.

changeShortcutWindow.once('ready-to-show', () => { // show gracefully, without a visual flash
    console.log("Ready to show");
    changeShortcutWindow.show();
  })

waiting for did-finish-load also did not help

changeShortcutWindow.webContents.on('did-finish-load', () => {
    console.log("finish load");
  })

awaiting loadURL also does not help.

await changeShortcutWindow.loadURL(CHANGE_SHORTCUT_WEBPACK_ENTRY);

NOTE: This seems to only happen during the first show of the window. Subsequent inits and shows of the window respect the background color.

Does anyone know how to prevent this?

I had this problem and fixed it by displaying offscreen then doing setPosition after ~100msec. Maybe a shorter delay could work too. Worked on windows, have not tried mac yet. Create the window with x=-20000, or calculate based on screens. Then just bw.setPosition(actualX, y).