slow download link with hostapd and ath9k_htc driver

**Brief Intro:** Raspberry Pi 3 acting as a WiFi AP hosting 2.4Ghz and 5Ghz Wifi AP's. The AP of concern is the 2.4Ghz network. The NIC is a TP-Link WN722N adapter using driver ath9k_htc. **Tests:** A speedtest done from the Raspberry Pi 3 results in: - Download: 21.69 Mbit/s - Upload: 18.32 Mbit/s which is expected and correct. Clients connecting to the 2.4Ghz hosted network doing a speedtest results in: - Download: 1-11 Mbit/s (AVG: 2.5 Mbit/s) - Upload: 14-18 Mbit/s *note: Changing router channels does not have any effect on the download speed of hosted wifi network.* A shared ethernet connection, hosted by the Raspberry Pi, to which clients connect do not experience this issue. These achieve expected download speeds. **Question:** Since all NIC's report correct download and upload speed except the hosted wifi network (2.4Ghz adapter) using the ath9k_htc driver has slow download speed, is this an issue with the ath9k_htc driver? **Some HW Info:** *note: The hosted 5Ghz network does not have this download issue, speeds are correct and as expected* NIC Info sudo lshw -C net *-usb:1 description: Wireless interface product: USB2.0 WLAN vendor: ATHEROS physical id: 3 bus info: usb@1:1.3 logical name: wlan2 version: 1.08 serial: 12345 capabilities: usb-2.00 ethernet physical wireless configuration: broadcast=yes driver=ath9k_htc driverversion=4.9.35-v7+ firmware=1.3 ip=192.168.2.254 link=yes maxpower=500mA multicast=yes speed=480Mbit/s wireless=IEEE 802.11 and hostapd config cat /etc/hostapd/hostapd-2g.conf interface=wlan2 driver=nl80211 ssid=local-wifi hw_mode=g channel=11 ieee80211n=1 wmm_enabled=1 ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40] macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=2 wpa_key_mgmt=WPA-PSK wpa_passphrase=my_pass_here rsn_pairwise=CCMP logger_syslog=-1