Bug 438274

SUMMARY

Running under Wayland, in touchpad settings, when first opened, the last setting is "Scrolling speed", and "Right-click" and "Middle-click" do not appear (but presumably should).  However, when Highlight Changed Settings is pressed, settings for "Right-click" and "Middle-click" appear, function properly, and persist after Highlight Changed Settings is disabled, but not when leaving/returning to the panel.

STEPS TO REPRODUCE / OBSERVED RESULT

As per summary; consistently happens for me with newly-opened system settings.  When highlight changed settings is turned off, the options remain, but when goig to another panel and returning, whether or not highlight changed settings is still on, the options disappear and do not return regardless of changes to highlight changed settings.

When present, the settings are completely functional, and the changed settings do persist properly.

EXPECTED RESULT

These settings should appear for this hardware: I actually found the behaviour while searching for them.  It is possible that there are two bugs here: that the settings are being incorrectly filtered out, and that highlight changed settings is breaking that filtering.  This may be related to 408116.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 34, kernel 5.12.5-300.fc34.x86_64
KDE Plasma Version: 5.21
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION

Computer is a Dell XPS 13 7390 2-in-1, touchpad output from libinput is:

Touchpad device DLL08BO:01 06CB:CD7A, on 

Device:           DLL08B0:01 06CB:CD7A Touchpad
Kernel:           /dev/input/event8
Group:            6
Seat:             seat0, default
Size:             108x63mm
Capabilities:     pointer gesture
Tap-to-click:     disabled
Tap-and-drag:     enabled
Tap drag lock:    disabled
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      n/a
Scroll methods:   *two-finger edge 
Click methods:    *button-areas clickfinger 
Disable-w-typing: enabled
Accel profiles:   flat *adaptive
Rotation:         n/a