P: (Mac) SDK - Floating dialog does not reopen on second screen

Environment

• Adobe Lightroom Classic 15.3
• Lightroom SDK
• macOS 26.5.1
• Standalone reproducer plugin attached

Summary

A floating dialog opened via `presentFloatingDialog()` does not reopen on the second screen. When the dialog is closed while positioned on a second monitor and then reopened, it always appears on the primary screen instead.
 

Steps to Reproduce

1. Connect a second monitor.
2. Install the attached reproducer plugin via File > Plug-in Manager > Add.
3. Run via Library > Plug-in Extras > Run Second Screen Dialog Bug Repro.
4. Choose "Test Floating Dialog".
5. Drag the dialog to the second screen.
6. Click "Close and Reopen".

A complete standalone reproducer plugin is attached.
 

Expected Result

The dialog reopens on the second screen at the position where it was last closed.
 

Actual Result

The dialog reopens on the primary screen. The position on the primary screen mirrors the saved coordinates — for example, a dialog closed at the top-left of the second screen reopens at the top-left of the primary screen — confirming that the coordinates are saved and restored correctly but the screen identity is not.

This behavior persists across a full LrC restart, confirming it is not a runtime state issue.
 

Additional Information

- `presentModalDialog()` is not affected — modal dialogs reopen correctly on the second screen.
- The attached reproducer plugin uses the standard SDK mechanism for persisting window position, with no custom positioning logic.
 

Impact

This prevents floating plugin dialogs from persisting their position on a second monitor. Any plugin using `presentFloatingDialog()` is affected.

A prominent real-world example is the Focus Points plugin (https://github.com/FocusPointsLrC/Focus-Points), which displays camera autofocus data in a dialog window. The upcoming version will feature a 'second screen' mode, in which the plugin sits as a floating dialog on the second screen and automatically responds whenever the user selects a different photo. This works well on Windows, but the workflow is unusable on macOS.
 

Attachments

Standalone reproducer plugin SecondScreenDialogBug.lrplugin.