Created attachment 153241 [details] what appears SUMMARY *** NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports *** STEPS TO REPRODUCE 1. Open Showfoto i.g. 2. Go to Color - > brightness/contrast/gamma 3. The bars at the right side have a bad appearance OBSERVED RESULT The bars have a vertical, instead of horizontal contrast (betweeen empty/full value) EXPECTED RESULT An horizontal contrast SOFTWARE/OS VERSIONS Linux/KDE Plasma: Operating System: KDE neon 5.26 KDE Plasma Version: 5.26.2 KDE Frameworks Version: 5.99.0 Qt Version: 5.15.6 Kernel Version: 5.15.0-52-generic (64-bit) Graphics Platform: X11 Processors: 2 × Intel® Core™ i3-7100 CPU @ 3.90GHz Memory: 7,7 GiB of RAM Graphics Processor: Mesa Intel® HD Graphics 630 Manufacturer: MSI Product Name: MS-7A74 System Version: 1.0 ADDITIONAL INFORMATION It happens using (some) gtk themes (such as Oxygen), not with Breeze theme.
I reported this bug, as an help request, on Italian Kubuntu forum (https://forum.ubuntu-it.org/viewtopic.php?f=73&t=650387&p=5316967#p5316967).