STEPS TO REPRODUCE
1. use Wayland session
2. make sure "Autosave file to default folder" is unchecked and "Copy image to clipboard" is selected in Spectacle settings
3. close Spectacle
4. try to take a screenshot by pressing shift+printscreen
screenshot should be taken and copied to clipboard
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.23.80
KDE Frameworks Version: 5.88.0
Qt Version: 5.15.3
Graphics Platform: Wayland
The issue here is that apparently nothing happens because the taken screenshot is not copied to clipboard and consequently Plasma does not display a notification.
*** This bug has been marked as a duplicate of bug 429390 ***
Humm, the screenshot should be saved after the provided steps despite broken "Copy image to clipboard" feature. On X11, the screenshot is saved after the provided steps, but on Wayland the screenshot is only saved if "Autosave file to default folder" is checked in Spectacle settings.