NSSavePanel ignores setDirectoryURL: on macOS Sequoia (15), always opens at last-used location

I have code in my macOS app that shows a save dialog using NSSavePanel. I want the panel to always open in a specific directory that I send as a parameter to my function. (e.g., /User/Desktop).

Here’s the simplified version of my code:

- (NSURL *)doSave:(NSURL *)initialLocation
     withFileName:(NSString *)fileName
         withTitle:(NSString *)title
{
    NSSavePanel *_savePanel = [NSSavePanel savePanel];

    // I want to force it to open here:
    [_savePanel setDirectoryURL:initialLocation];
    [_savePanel setNameFieldStringValue:fileName];
    [_savePanel setTitle:title];

    if ([_savePanel runModal] == NSModalResponseOK) {
        return [_savePanel URL];
    }
    return nil;
}

On macOS Sonoma (14) and earlier, this worked: The dialog always opened at initialLocation.

But on macOS Sequoia (15), the panel always opens at the last location where a file was saved (system-wide), even though I set directoryURL.

I tried:

1. Clearing the identifier (_savePanel.identifier = nil)

2. Setting _savePanel.restorable = NO.

3. Clearing NSUserDefaults keys like NSNavLastRootDirectory.

4. Resetting directoryURL right before runModal.

But Sequoia still restores the last-used location, seemingly overriding directoryURL.

How can I force NSSavePanel to honour setDirectoryURL: on Sequoia (macOS 15)? Did Apple change the expected way to set the initial directory? Is there a new API or flag to disable the "last-used folder" behaviour?

Additional observation (LLDB):

// Right after creating the save panel:
(lldb) po [_savePanel directoryURL]
file:///User/Documents/    // Last used folder 

// After calling setDirectoryURL:initialLocation:
(lldb) po [_savePanel directoryURL]
nil                       // My assignment was wiped out

I found out that if I use the old API setDirectory: (which is deprecated), the panel does open in the folder we specify and doesn’t get overridden by the system. But I can't rely on a deprecated API.