Ha..found the solution.
Disconnect from the Internet
Reverse to the previous firmware.
And then follow this article: https://community.netgear.com/t5/Orbi/Firmware-V1-12-0-18-Discussion/td-p/1320421/page/5 from Butch1326
To stop the Orbi from installing the updated firmware automatically follow the steps below.
Perform these step after you downgraded the firmware to a prior release.
1) Launch your favorite web browser and go to <Router IP Address>/debug.htm
2) Login <username> <password> when prompted
3) Check Enable Telnet
4) Start a Telnet session. I use Putty. Enter the <Router IP Address> Telnet is using port 23
5) You can skip this step if you like. I am calling it out for illustration purposes only...
Type nvram show | grep auto_* <ENTER>
You will see a list similar to this:
root@RBR50:/# nvram show | grep auto_
vpn_access_mode=auto
wl_auto_antenna=1
set_auto_agreement=0
orbi_auto_upgrade=1
ipv6_autoConfig_dns_assign=0
ipv6_autoConfig_dns1=
ipv6_autoConfig_dns2=
upnp_enable_autoScan=0
ipv6_auto_dns_assign=0
bas_auto_conn_flag=0
orbi_auto_upg=0
autofw_port0=
ipv6_auto_dns1=
ipv6_auto_dns2=
qos_auto_bandwidth=0
green_enable_autorefresh_status=0
enable_dev_auto_refresh=1
wl_rate=auto
auto_check_for_upgrade=1
auto_update=1
root@RBR50:/# root@RBR50:/#
The 3 configurations highlighted above you will want to update the value from =1 to =0
orbi_auto_upgrade=1
auto_check_for_upgrade=1
auto_update=1
6) To update run the following commands:
nvram set orbi_auto_upgrade=0 <ENTER> (no spaces after set)
nvram set auto_check_for_upgrade=0 <ENTER> (no spaces after set)
nvram set auto_update=0 <ENTER> (no spaces after set)
7) Type the following commands to confirm the 3 configurations are set to =0
nvram show | grep orbi_auto_upgrade <ENTER>
nvram show | grep auto_check_for_upgrade <ENTER>
nvram show | grep auto_update <ENTER>
😎 After you confirmed the 3 configuration values are set to =0 then type nvram commit<ENTER> (this step will save the changes)
9) Type exit to terminate the telnet session
10) Go back to the <Router IP Address>/debug.htm web page and uncheck Enable Telnet
Please note within a day or so the Orbi will know there is an updated firmware release available but it will not automatically install it. If you do go back into a Telnet session after the Orbi knows there is an updated firmware release the configuration orbi_auto_upgrade will have a value greater than 1. That is okay. Do not change the value back to =0
