External fullscreen window extends onto primary monitor after Stop when secondary display is positioned above primary

[ravishi77]

Description
I use SMPlayer's external screen feature to send fullscreen video to a projector while keeping the SMPlayer interface on the primary monitor.

The video plays correctly when the projector is positioned above the primary display in Windows Display Settings.

However, when I press Stop, a black fullscreen overlay/window appears on the projector and is incorrectly positioned/sized: it extends downward over the upper part of the primary monitor.

If I press Play again, the fullscreen video is also affected and is drawn larger than the projector area.

To Reproduce
Steps to reproduce the behavior:

1. Connect two 1920×1080 displays.
2. Set Windows Display Settings so that the secondary display is positioned above the primary display.
3. In SMPlayer, enable sending video to the secondary screen.
4. Play a video in fullscreen mode.
5. Press Stop.

Expected behaviour
The external video window should remain confined to the geometry of the selected display.

Actual result
The black fullscreen window extends beyond the secondary display and covers part of the primary display.

Screenshots
https://snipboard.io/MqZnQC.jpg (black overlay drawn when Stop pressed)
https://snipboard.io/0afbyL.jpg (video fills black overlay upon Play)
https://snipboard.io/ARMSgn.jpg (sideways screens work well, no issue @Detected)

My Enviroment
OS: Windows 10 Pro
SMPlayer: 25.6.0 (revision 10369) (64-bit)
Qt: 5.15.2
Multimedia engine: mpv v0.37.0-522-ga56d8ff1
Primary display: 1920×1080, Windows scaling 100%
Secondary display: Epson EB-1980WU projector, 1920×1080, Windows scaling 100%

Additional tests
The problem does not occur when the secondary display is positioned to the right of the primary display.
Both displays use identical resolution and 100% scaling.
The issue persists after updating from SMPlayer 23.12.0 to 25.6.0.
I couldn't reproduce the error on another Lenovo laptop...

Additional context
The bug appears immediately when pressing Stop; it is not only a playback restart issue.
This may be related to handling a display with a negative Y coordinate in a multi-monitor layout (secondary display positioned above the primary display).

SMPlayer Logs
Log too long for this forum! I can paste relevant lines from the log upon request. Or post it somewhere.