from wpa_cli I can see that all APs support wpa2 FT, but when the roaming happens, these are the logs from the AP:
at Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI IEEE 802.11: authentication OK (open system)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: event 0 notification
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI MLME: MLME-AUTHENTICATE.indication(MACADDR_CLI, OPEN_SYSTEM)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI MLME: MLME-DELETEKEYS.request(MACADDR_CLI)
Sat Dec 9 19:44:22 2017 daemon.info hostapd: wlan0: STA MACADDR_CLI IEEE 802.11: authenticated
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI IEEE 802.11: association OK (aid 2)
Sat Dec 9 19:44:22 2017 daemon.info hostapd: wlan0: STA MACADDR_CLI IEEE 802.11: associated (aid 2)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI MLME: MLME-REASSOCIATE.indication(MACADDR_CLI)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI MLME: MLME-DELETEKEYS.request(MACADDR_CLI)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI IEEE 802.11: binding station to interface 'wlan0'
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: event 1 notification
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: sending 1/4 msg of 4-Way Handshake
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: received EAPOL-Key frame (2/4 Pairwise)
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: sending 3/4 msg of 4-Way Handshake
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI WPA: received EAPOL-Key frame (4/4 Pairwise)
Sat Dec 9 19:44:22 2017 daemon.notice hostapd: wlan0: AP-STA-CONNECTED MACADDR_CLI
Sat Dec 9 19:44:22 2017 daemon.debug hostapd: wlan0: STA MACADDR_CLI IEEE 802.1X: authorizing port
Sat Dec 9 19:44:22 2017 daemon.info hostapd: wlan0: STA MACADDR_CLI RADIUS: starting accounting session 884C0F5437F4D26E
Sat Dec 9 19:44:22 2017 daemon.info hostapd: wlan0: STA MACADDR_CLI WPA: pairwise key handshake completed (RSN)
As you can see, every time it uses WPA 4way handshake instead of FT.
I’m not 100% sure, because I cannot find more infos about how to check if client support it, but as of now I tried also with huawei honor 9, that is a fairly recent mobile phone, and also an iphone 7, and no one uses FT
Now I'm trying on a different device, a netgear R8000: when I enable 802.11r, the client can see the connection but cannot connect to the station. The configuration is similar to the one reported on the reddit topic, Is there something wrong with broadcom boards + 802.11r?
you might well need the full version of dnsmasq to get FT working.
It's hard to get info on 802.11r support, some Samsung phones advertise it in the small print, but I think still most android phones don't support it even brand new ones.
I really can't say for sure, but that's what I suspect is that you need hostapd full for 802.11r. I tried to set this up too, and it shows as FT supported on Wifi Analyzer, but my older moto g3 doesn't support it so I don't get any benefit... eventually when I upgrade my phone I'm hoping to finally have decent fast roaming, particularly for VOIP it's no good the 1/2 second to 1 second drop-outs during handoff.
EDIT: and yes, I installed hostapd full and I think that means I needed wpa_supplicant and uninstall wpad
unfortunately, with android there are not too many devices that support 802.11r. I've just bought a huawei honor 9, and it does not support it. The only mobile devices that supports r/k/v for sure are the apple ones....