*** 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 When, in Calibre viewer, you open the Table of Content (TOC) pop-up window, in Wayland, you cannot see it, because it goes always behind the main window. So you have every time anew to work to move it in a visible place (aside the main window). Unless you let it inside the main window. STEPS TO REPRODUCE 1. Open a book with Calibre e-book viewer 2. Open the TOC window 3. OBSERVED RESULT The TOC window by default goes behind, of, if closed before (covering the main window) EXPECTED RESULT TOC window should go (appear) when it was the previous time (typically at the side, left or right of the main window). SOFTWARE/OS VERSIONS Operating System: KDE neon User Edition KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.21.0 Qt Version: 6.10.1 Kernel Version: 6.14.0-37-generic (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5700G with Radeon Graphics Memory: 16 GiB of RAM (13,5 GiB usable) Graphics Processor: AMD Radeon Graphics ADDITIONAL INFORMATION I reported this problem on Calibre bugs, but they said that this is not their fault, a problem of Calibre, but a Wayland problem.