[BUG] Drag and drop document tab to taskbar moves the window outside desktop borders

Is there an existing issue for this?

• I have searched the existing issues

Is the issue reproducible in Notepad++ without plugin?

• I have tried Notepad++ without plugin

Is the issue reproducible in portable version of Notepad++?

• I have tried portable version of Notepad++

Does the issue affect SciTE?

• I have tried SciTE

Description of the Issue

It is possible to have multiple instances of the app even if "Default (mono-instance)" is selected in "Multi-instance settings". You just have to drag and drop a document from the tab bar to the Windows taskbar. But when you do that the new window is not shown in the desktop, because the coordinates of the new window are outside the desktop.

Steps To Reproduce

1. Run the app and open existing document.
2. Start drag and drop on document's tab. Mouse pointer will change shape.
3. Move mouse to taskbar. Mouse pointer changes shape again.
4. Drop the document to taskbar. If the document is the only one open then current app instance will end, and new one will start. But the window is not shown on desktop. The window exists, but its coordinates are outside the desktop.
5. Press Alt+Space, then M, then arrow key Up. Small part of the window will appear. Now when you move mouse the window will move with it.

Current Behavior

Drag-n-drop is allowed, but the new window is not shown in the desktop.

Expected Behavior

The new window should be shown in the desktop without having to use Alt+Space,M technique.

Debug Information

Notepad++ v8.8.8   (64-bit)
Build time: Nov 16 2025 - 20:55:01
Scintilla/Lexilla included: 5.5.7/5.4.5
Boost Regex included: 1_85
Path: C:\Program Files\Notepad++\notepad++.exe
Command Line: "C:\Users\Dialecticus\Downloads\Known attribute keys.txt" -multiInst -nosession -x864 -y1051 -lnormal -n1 -c1
Admin mode: OFF
Local Conf mode: OFF
Cloud Config: OFF
Periodic Backup: OFF
Placeholders: OFF
Scintilla Rendering Mode: SC_TECHNOLOGY_DEFAULT (0)
Multi-instance Mode: monoInst
asNotepad: OFF
File Status Auto-Detection: cdEnabledNew (for current file/tab only)
Dark Mode: OFF
Display Info:
    primary monitor: 1920x1080, scaling 100%
    visible monitors count: 1
    installed Display Class adapters: 
        0001: Description - Intel(R) UHD Graphics 620
        0001: DriverVersion - 27.20.100.8477
        0002: Description - NVIDIA GeForce 940MX
        0002: DriverVersion - 30.0.15.1169
OS Name: Windows 10 Pro (64-bit)
OS Version: 22H2
OS Build: 19045.6456
Current ANSI codepage: 1252
Plugins: 
    ComparePlugin (2.0.2)
    mimeTools (3.1)
    NppConverter (4.7)
    NppExport (0.4)
    NPPJSONViewer (2.0.6)
    XMLTools (3.1.1.13)

Anything else?

No response

No source file, test, or entry point is named. First reproduce the drag-and-drop from a document tab to the Windows taskbar under the reported mono-instance settings, then trace the new window's position and compare it with the desktop bounds; done means the new window appears on the desktop without the Alt+Space, M workaround.