Created attachment 168080 [details] Demonstration of the bad behaviour *** If you're not sure this is actually a bug, instead post about it at https://discuss.kde.org If you're reporting a crash, attach a backtrace with debug symbols; see https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports *** SUMMARY After switching to a non-default activity and back, kwin looses track of z-indexes of overlapping windows. A window will appear at the top and yet be completely click-through with its inputs being captured by the window under it. Focusing a different window will result in a nonsensical reordering of z-indexes of overlapping windows. The only fix I found is restarting the session. STEPS TO REPRODUCE (as seen in attached video) 1. I demonstrate normal behaviour of selecting focusing windows on the default activity (orange wallpaper) 2. I switch to an alternative activity (blue wallpaper) and demonstrate that window focus still works well 3. I switch back to the default activity (orange wallpaper) and demonstrate that windows are now no longer being focused properly. OBSERVED RESULT Windows at the top don't capture mouse input, cannot be clicked even when clicking its window decoration, focused window often does not appear at the top. EXPECTED RESULT Window at the top always captures mouseclicks and mouse hover. SOFTWARE/OS VERSIONS Operating System: openSUSE Tumbleweed 20240329 KDE Plasma Version: 6.0.3 KDE Frameworks Version: 6.0.0 Qt Version: 6.6.3 Kernel Version: 6.8.1-1-default (64-bit) Graphics Platform: Wayland Processors: 12 × AMD Ryzen 5 5500U with Radeon Graphics Memory: 15.0 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: LENOVO Product Name: 82HU System Version: IdeaPad Flex 5 14ALC05