NetworkManager seems to enable Protected Management Frames even if the driver doesn't support it
I'm not sure if this is the right place for this report (if this even has to do with NetworkManager itself), to be honest.
So when I wanted to connect to an Access Point that supports PMF (but doesn't require it), I wasn't able to connect to that AP with default connection settings ("wifi-sec.pmf" set to optional) with networkmanager 1.14.5dev+17+gba83251b-1.
The wpa_supplicant log only prints the following messages and then disconnects with reason "unspecified":
Jan 07 19:22:51 arch-desktop wpa_supplicant[491]: wlp6s0: WPA: Failed to configure IGTK to the driver
Jan 07 19:22:51 arch-desktop wpa_supplicant[491]: wlp6s0: RSN: Failed to configure IGTK
Turns out that "IGTK" stands for "Integrity Group Temporary Key" which is used with PMF to encrypt broadcast frames. If I understood the issue correctly the problem is that my network driver doesn't support the cipher suites requested by the AP.
After disabling PMF for the connection with the following command I could connect to the AP again:
nmcli connection modify <connection> wifi-sec.pmf disable
Again I'm not sure if this is the right place for this issue (I'm sorry if it isn't), but I figured it might be as using wpa_supplicant directly seems to work just fine without disabling PMF explicitly. Also, I'm really not an expert with this, let me know if more detail is needed.