Left clicking disables itself from time to time. Either when reopening the laptop lid/exiting sleep, disconnecting from an external display, or sometimes even randomly. Whenever that happens, two-finger scrolling doesn't work. It's not a hardware issue because connecting a mouse doesn't work either. A reboot fixes it, but rebooting over and over again gets annoying.

OS: Manjaro Linux x86_64
Host: Blade Stealth 13 (Early 2020) - RZ09-0310 2.04
Kernel: 5.15.21-1-MANJARO
DE: Plasma 5.23.5

Only since the latest Plasma update I experience a similar issue a in vanilla Arch setup: In System settings, I set my mouse wheel direction to inverse, and it works as expected. After resuming from standby, I'm back to normal wheel direction (while the System settings dialog still pretends I'd be inverse). Setting it to "normal" and Activate the setting, it remains "normal". Setting it to "inverse" and Activate the setting brings me back to inverse scrolling (until the next standby).

Edit 2022 Sep, 10th: Fixed in 5.24.7 / 5.25.0 according to this bug: https://bugs.kde.org/show_bug.cgi?id=435113.

It turns out to be more of hardware issue. After waking up form sleep, the touchpad thinks it's holding the left click. As a workaround, I've assigned a keyboard shortcut to enabling/disabling the touchpad, which cancels the left click and makes it work as normal.