If you're having an issue with wifi, getting "deauthenticating [...] by local choice (Reason: 1=UNSPECIFIED)" in dmesg,
and "Failed to configure IGTK" in wpa_supplicant logs
it's probably 80211w.
Found this blog post that describes the issue https://ettore.dreucci.it/blog/failed-to-configure-igtk/
In my case it's extra annoying because since January (yes I know I should update arch most often), netctl unconditionally sets ieee80211w=1 in wpa_supplicant.conf.
It doesn't check if the card supports it.
It doesn't have an option to override it.
wpa_supplicant doesn't check if the card supports it either.