Installing the KDE power management controls fixed the issue!

While working remotely now I just discovered two things that are annoying with
the XPS 13 Plus and Arch Linux: the webcam is not yet supported (it seems to
work in Ubuntu),

and this @AnkerOfficial hub fails to
register fully as a sound device when using it with Keyboard and Mouse: Anker
565 11-in-1 USB-C Hub, 10...
https://www.amazon.de/dp/B09Q3LJMFT?ref=ppx_pop_mob_ap_share