SUMMARY In applications that use the WebView component (e.g. KMail, Falkon), touch-pad scrolling (e.g. two-finger scrolling) doesn't work with the WebView component. In particular, in Kontact, two-finger scrolling works with every _other_ widget, just not the Mail View widget, which uses a WebView to render E-mails. SOFTWARE/OS VERSIONS Operating System: KDE neon 5.24 KDE Plasma Version: 5.24.2 KDE Frameworks Version: 5.91.0 Qt Version: 5.15.3 Kernel Version: 5.13.0-30-generic (64-bit) Graphics Platform: Wayland Processors: 2 × AMD A6-9220C RADEON R5, 5 COMPUTE CORES 2C+3G Memory: 3.8 GiB of RAM Graphics Processor: AMD STONEY
Very likely an issue in that component itself, but I'll let the KWin folks confirm or deny that theory.
Most likely a bug in WebView. But I'm not familiar with Kontact/KMail codebase.