The current config is:
0 R name="W_AP" mtu=1500 l2mtu=1600 mac-address=********* arp=enabled disable-running-check=no interface-type=Atheros AR9888 radio-name="*******"
mode=ap-bridge ssid="********" area="" frequency-mode=manual-txpower country=no_country_set antenna-gain=0 frequency=5200 band=5ghz-onlyn
channel-width=20/40mhz-Ce scan-list=default wireless-protocol=802.11 rate-set=default
supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps basic-rates-a/g=6Mbps max-station-count=2007 distance=dynamic tx-power=30
tx-power-mode=all-rates-fixed vlan-mode=no-tag vlan-id=1 wds-mode=disabled wds-default-bridge=none wds-default-cost=100 wds-cost-range=50-150
wds-ignore-ssid=no update-stats-interval=disabled bridge-mode=enabled default-authentication=yes default-forwarding=no default-ap-tx-limit=0
default-client-tx-limit=0 wmm-support=enabled hide-ssid=no security-profile=poa wps-mode=push-button station-roaming=enabled disconnect-timeout=3s
on-fail-retry-time=100ms preamble-mode=both compression=no allow-sharedkey=no station-bridge-clone-mac=00:00:00:00:00:00 ampdu-priorities=0
guard-interval=any ht-supported-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7,mcs-8,mcs-9,mcs-10,mcs-11,mcs-12,mcs-13,mcs-14,mcs-15,mcs-16,mcs-17,mcs-
18,mcs-19,mcs-20,mcs-21,mcs-22,mcs-23
ht-basic-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7 vht-supported-mcs=mcs0-9,mcs0-9,mcs0-9 vht-basic-mcs=mcs0-7 tx-chains=0,1 rx-chains=0,1
amsdu-limit=8192 amsdu-threshold=8192 tdma-period-size=2 nv2-queue-count=2 nv2-qos=default nv2-cell-radius=30 nv2-security=disabled nv2-preshared-key=""
nv2-mode=dynamic-downlink nv2-downlink-ratio=50 nv2-sync-secret="" hw-retries=2 frame-lifetime=100 adaptive-noise-immunity=ap-and-client-mode
hw-fragmentation-threshold=disabled hw-protection-mode=none hw-protection-threshold=512 frequency-offset=0 rate-selection=advanced
multicast-helper=default multicast-buffering=enabled keepalive-frames=enabled pci-info="00:00.0"
Have changed to N-only and seeing the same effects. I can improve throughput by adjusting settings, but the complete cut-offs happen no matter what.