Undo History won't clear if popupmenu checked

Hello

I've a simple script that clears the Undo History queue. If I comment out lines 13-25, the script works fine, but if I check to see if the "Clear Undo Queue" menuitem is enabled, the script fails with 'Popup menu was not found'. I've confirmed it is enabled and there are Undo steps in the queue.
Specifically, if I have the line const undoHistoryMenu = undoHistoryBtn.popupMenuFetchAllItems().menuItems, it breaks. How does fetching the popupmenu cause the popupMenuSelect to fail?

What am I doing wrong here?

sf.ui.proTools.appActivateMainWindow();
log('Attempting to clear Undo History...');

// Open the Undo History window
sf.ui.proTools.menuClick({ menuPath: ["Window", "Undo History"], targetValue: "Enable" });

// Define the Undo History button that opens the menu
const undoHistoryBtn = sf.ui.proTools.windows.whoseTitle.is("Undo History").first
    .children.whoseRole.is("AXMenuButton").whoseTitle.is("Undo Actions").first;


// This below section of code works correctly if the "Clear Undo Queue" button is greyed out, but fails if it's not
/* // Fetch all enabled menu items for the undo history button
let undoHistoryMenu = undoHistoryBtn.popupMenuFetchAllItems().menuItems
    .filter(mi => mi.element.isEnabled)
    .map(mi => mi.path.join(" > ")); 

log(undoHistoryMenu)

// Check if "Clear Undo Queue" exists in the enabled menu items
if (!undoHistoryMenu.includes("Clear Undo Queue")) {
    log("No Undo History to delete.");
    throw 0; // Exit if no Undo History items are available to delete
}  */

// Otherwise, clear the undo queue
undoHistoryBtn.popupMenuSelect({
    menuPath: ["Clear Undo Queue"],
});

// Confirm the action if a confirmation dialog appears
if (sf.ui.proTools.confirmationDialog.exists) {
    const yesButton = sf.ui.proTools.confirmationDialog.buttons.whoseTitle.is("Yes").first;
    if (yesButton.exists) {
        yesButton.elementClick();
        sf.ui.proTools.confirmationDialog.elementWaitFor({ waitType: "Disappear" });
    }
}

log('Undo History cleared.');

// Close the Undo History window
sf.ui.proTools.menuClick({ menuPath: ["Window", "Undo History"], targetValue: "Disable" });