NETGEAR R6220 multple wireless interface

Having an issue with this router. Latest version of LEDE snapshot. If I have 2 interface per radio (1 client 1 AP) the AP becomes very intermittent. If the 2GHZ radio is client and 5GHZ is AP, and vice versa, it works, but obviously much slower.

checking logread

disconnected due to excessive missing ACKs

the software it is not smart enought to know that don't have to connect to itselft, if you have same wifi chipset hardware manufacturer on both, client and ap (of the linked ones) you could try to enable wds on both, and you have to ways to get it working... use bssid field on the client to force the client iface to connect to the other AP and not to itselft, create two ifaces on the main one, one called "link" and hide it, and use that ssid on the client iface too, and have the "your wifi network" ssid on other one and repeat on the client ap... (in that way the "link" network will be used to connections from one device to another and other devices will not interfere in connection)

I have a sample configuration here: https://gist.github.com/braian87b/8a524a8ad74a36407a8f481e9d16a5c9

Sadly, they're not the same chipset.
I have tried another Linksys and NETGEAR router in the past for this exact same reason, and they worked fine doing the same as I did now. Maybe my configurations are wrong. "option disassoc_low_ack 0" doesn't prevent it either.

do a uci show wireless on the LEDE router, that will show inmediatly if the config need bssid field, if you have same ssid on ap and sta ifaces it is needed since it will try to connect to itselft.

root@LEDE_AP:~# uci show wireless
wireless.radio0=wifi-device
wireless.radio0.type='mac80211'
wireless.radio0.hwmode='11g'
wireless.radio0.path='pci0000:00/0000:00:01.0/0000:02:00.0'
wireless.radio0.htmode='HT40'
wireless.radio0.country='US'
wireless.radio0.txpower='27'
wireless.radio0.channel='1'
wireless.radio1=wifi-device
wireless.radio1.type='mac80211'
wireless.radio1.hwmode='11a'
wireless.radio1.path='pci0000:00/0000:00:00.0/0000:01:00.0'
wireless.radio1.htmode='VHT80'
wireless.radio1.country='US'
wireless.radio1.disabled='0'
wireless.radio1.channel='36'
wireless.radio1.txpower='23'
wireless.radio1.log_level='1'
wireless.@wifi-iface[0]=wifi-iface
wireless.@wifi-iface[0].network='wwan'
wireless.@wifi-iface[0].ssid='n20-5G'
wireless.@wifi-iface[0].encryption='psk2'
wireless.@wifi-iface[0].device='radio1'
wireless.@wifi-iface[0].mode='sta'
wireless.@wifi-iface[0].bssid='00:15:3C:15:CB:66'
wireless.@wifi-iface[0].key='password'
wireless.@wifi-iface[1]=wifi-iface
wireless.@wifi-iface[1].device='radio1'
wireless.@wifi-iface[1].mode='ap'
wireless.@wifi-iface[1].ssid='n20-5G-EXT'
wireless.@wifi-iface[1].network='lan'
wireless.@wifi-iface[1].encryption='psk2'
wireless.@wifi-iface[1].key='password'
wireless.@wifi-iface[1].disassoc_low_ack='0'
root@LEDE_AP:~#

Your setup is Routed Client, if BSSID is correct and the other Router is acting emitting just one SSID with BSSID 00:15:3C:15:CB:66, with dhcp enabled it should work (if you have two SSID with same BSSID then could be conflict when chosing to which one to connect). Check if other Router have channel 36 fixed, since you set as fixed too, if not, set it to 'auto' on both, but you will have some disconnections. You could try to use another channel too, above 100.

I have a sample configuration file here, but yours seems to be fine... https://gist.github.com/braian87b/2333a32577a221c8d62b5ce8b54a4d95

The main problem I'm facing now.

If router B connects to router A using 5GHz (client), a 5GHz (master) becomes intermittent). If I use 2.4GHz (client) and 5GHz (master) then things are just really slow, still. Maybe it's a driver limitation?

I keep getting this in logs, If i have a 5GHz client/master in router B.

Thu Jul 6 13:36:27 2017 daemon.info hostapd: wlan1-1: STA PHONE:MAC IEE E 802.11: disconnected due to excessive missing ACKs

follow up: Netgear r6220 ap issue