Created attachment 152219 [details]
Video showing the unhelpful ping-pong 'progress' bar

STEPS TO REPRODUCE
1. have a 7zip archive - I tested single volume and multi-volume 7zip archives on my system
2. extract your 7zip archive via context menu of Dolphin - I use 'Extract archive here, autodetect subfolder' option
3. 

OBSERVED RESULT
while the 7zip archive is extracted, Plasma shows a notification with the unhelpful ping-pong 'progress' bar
seen in the attached screen recording (in the video I'm creating an archive, but the same 'progress' bar appears after the provided steps).

EXPECTED RESULT
the progress bar should tell us the real progress of the extraction

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.25.90
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Graphics Platform: Wayland