Prusaslicer exports for print the last sliced object instead of the intended print when using multiple windows

[NHodgesVFX]

Description of the bug

When working with multiple windows of Prusaslicer, PrusaSlicer will export for print the last sliced object and not currently focused window's object, where the export or send to printer button is clicked.

Project file & How to reproduce

1. Open PrusaSlicer, add something to print and slice it.
2. Open 2nd PrusaSlicer process / window, add something to print and slice it.
3. Go back to the first window and send the GCode to the printer or export it.

Result: The printer starts printing the object from the 2nd process not the 1st one. Or if you open the exported GCode in the GCode viewer you see an object from the 2nd process not the first one.

Also, notice the name of the file correlates to the first process, despite printing the object from the 2nd process.

Expected Result: When using multiple windows the object of the focused window, where the button is clicked, is printed or exported not the last sliced object of any PrusaSlicer process.

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.9.0

Operating system

Kubuntu 24.04

Printer model

Prusa XL 5 Tool