Gregory's Server
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.
It's also a weird issue in that it needs to also be enabled on the AP for this to happen, and I was like "oh, cool, OpenWrt has such cool features like management frame protection, I'll enable it on my internal wifi for extra security".
Well, had to disable it afterall.