Created attachment 188016 [details]
screenshot of the taskbar and game

SUMMARY
Not entirely sure where else to report this bug since I'm running the Windows build of Dosbox inside Proton.
This is only necessary since I'm also running Goldbox Companion which has no corresponding Linux build.

TLDR is that if you launch the portable Windows build of Dosbox which comes with any Goldbox game that's normally shipped by GOG using Goldbox Companion the taskbar is no longer able to hide.

STEPS TO REPRODUCE
1. Set taskbar to autohide
2. Download the GOG release of Goldbox Companion
3. Download a supported title like "Pool of Radiance"
4. Launch GBC using GEProton10-27 or 9-27
5. Make any necessary Dosbox configuration changes then launch the game (disable cursor lock, run in windowed, etc)
6.  Once the game is up and running create a save 
7.  Navigate back to Goldbox Companion Window and select the save letter, then press search.
8.  Once GBC is able to find the game it will automatically mount the corresponding windows (automap, etc) to the Dosbox window.
9.  The taskbar which has been set to autohide is no longer able to hide.

OBSERVED RESULT
The taskbar is no longer able to hide.

EXPECTED RESULT
It should hide just as it was before GBC locked onto the Dosbox save.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.17.12-300.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7800X3D 8-Core Processor
Memory: 32 GiB of RAM (31.0 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 4090

ADDITIONAL INFORMATION
The only way around for this is by disabling "Unhide when a window wants attention" under Icons-Only taskbar settings OR by creating a Windows Rule which allows the application to skip the taskbar. 

I've also had some limited success by bringing up the "Panel Configuration" menu then immediately exiting Edit Mode.