How do we enable 5GHz wifi for the AC8265

I’m having trouble enabling 5GHz for the AC8265 chip on the Xavier so I can have higher bandwidth. My hostapd looks like:

interface=wlan0
hw_mode=a
channel=0
auth_algs=1
driver=nl80211
ieee80211d=1
country_code=US
ieee80211n=1
ieee80211ac=1
wmm_enabled=1
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
wpa_passphrase=0000000000
ssid=AGX-1
wmm_enabled=1
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

I’ve only been successful at enabling 2.4Ghz with this config:

interface=wlan0
hw_mode=g
channel=4
auth_algs=1
driver=nl80211
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
wpa_passphrase=0000000000
ssid=AGX-1
ieee80211n=1
wmm_enabled=1
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

Is there some sort of restriction where I can’t enable a 5GHz network? If so, how do I get around it? Is there a kernel patch which I need to apply?