iwinfo gives this on my X5000R:
wlan0 ESSID: "xxxxxx"
Access Point: 5C:92:5E:9B:FF:50
Mode: Master Channel: 11 (2.462 GHz)
Center Channel 1: 11 2: unknown
Tx-Power: 20 dBm Link Quality: 42/70
Signal: -68 dBm Noise: unknown
Bit Rate: 47.9 MBit/s
Encryption: WPA2 PSK (CCMP)
Type: nl80211 HW Mode(s): 802.11bgn
Hardware: 14C3:7915 14C3:7915 [MediaTek MT7915E]
TX power offset: none
Frequency offset: none
Supports VAPs: yes PHY name: phy0
wlan1 ESSID: "xxxxxx"
Access Point: 00:0C:43:4A:21:4E
Mode: Master Channel: 36 (5.180 GHz)
Center Channel 1: 42 2: unknown
Tx-Power: 20 dBm Link Quality: 43/70
Signal: -67 dBm Noise: unknown
Bit Rate: 563.3 MBit/s
Encryption: WPA2 PSK (CCMP)
Type: nl80211 HW Mode(s): 802.11nac
Hardware: 14C3:7915 14C3:7915 [MediaTek MT7915E]
TX power offset: none
Frequency offset: none
Supports VAPs: yes PHY name: phy1
Does this mean the ax mode is not enabled?