Android phone disconnects right after connecting

[Marsfan]

I just this past week got a Netgear R7800 WiFi router and I installed OpenWRT 21.02.
My laptop connects to the WiFi just fine, but my phone will connect, and then quickly disconnects. After a few seconds, then repeats this process. As a result, I cannot get my phone to work on the WiFi connection.

My phone is a Moto G5+ running Android 8

The syslog in LuCI shows the following for every single connect/disconnect

Thu Oct 14 19:58:18 2021 daemon.info hostapd: wlan0: STA dc:bf:e9:a5:1a:9c IEEE 802.11: authenticated
Thu Oct 14 19:58:18 2021 daemon.info hostapd: wlan0: STA dc:bf:e9:a5:1a:9c IEEE 802.11: associated (aid 3)
Thu Oct 14 19:58:18 2021 daemon.notice hostapd: wlan0: AP-STA-CONNECTED dc:bf:e9:a5:1a:9c
Thu Oct 14 19:58:18 2021 daemon.info hostapd: wlan0: STA dc:bf:e9:a5:1a:9c WPA: pairwise key handshake completed (RSN)
Thu Oct 14 19:58:18 2021 daemon.info dnsmasq-dhcp[12803]: DHCPDISCOVER(br-lan) dc:bf:e9:a5:1a:9c
Thu Oct 14 19:58:18 2021 daemon.info dnsmasq-dhcp[12803]: DHCPOFFER(br-lan) 10.0.0.189 dc:bf:e9:a5:1a:9c
Thu Oct 14 19:58:18 2021 daemon.info dnsmasq-dhcp[12803]: DHCPREQUEST(br-lan) 10.0.0.189 dc:bf:e9:a5:1a:9c
Thu Oct 14 19:58:18 2021 daemon.info dnsmasq-dhcp[12803]: DHCPACK(br-lan) 10.0.0.189 dc:bf:e9:a5:1a:9c
Thu Oct 14 19:58:23 2021 daemon.notice hostapd: wlan0: AP-STA-DISCONNECTED dc:bf:e9:a5:1a:9c

I tried following unchecking the "Disassociate On Low Acknowledgement" on LuCI. but I still have the issue.

What other things should I try to get my phone to stay connected to my network?

[erdoukki]

Have you tried to disconnect the computer to see if the smartphone then still get disconnect or get access ?
I have seen this on 8997 with most recents firmware which works only with one client at a time !

[Marsfan]

@erdoukki That did not fix it.
I also tried disabling just one of the 2.4GHz and 5GHz interfaces, and disabling the mobile data on my phone.

Neither of those fixed it either.

[Marsfan]

I figured it out. I had a non-existent IPv6 address set as the IPv6 DNS server.(due to it changing between the time I set it and the time my phone connected). Apparently that was enough for Android to decide to kick itself off of the network.
Now I need to set a static IPv6 address with my Pi-Hole so that I can go back to using it as an IPv6 DNS server.