SUMMARY
Dragging the volume widget's slider lags behind UI-wise. It *seems* like it only moves the position after the OSD's volume slider moved to the correct position, but haven't tried to measure it exactly.

STEPS TO REPRODUCE
1. Have volume at ~50%
2. Open volume widget
3. Drag the handle first to ~100%, then to ~10% without letting go, fast-ish

OBSERVED RESULT
It will take a long time until the handle is actually at its ~10% position.

EXPECTED RESULT
The handle should always be synchronized with the mouse cursor.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0
Kernel Version: 6.14.6-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 1600 Six-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: AMD Radeon RX 570 Series
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: B450M DS3H

ADDITIONAL INFORMATION
Oliver Beard suspected a QT 6.9.0 regression. I instinctively wanna say that this happened before the 6.9.0 release, but don't have any quick way to check right now.