RBK750 Series - Firmware Update v4.6.3.7

Here is the latest update from my trying:

1.  Downgrade the Firmware to  V3.2.10.10  for both Router and the Satellite, which is the very first Firmware version.   Using the way I mentioned in previous thread that pressing F12 in the downgrade page and unhide the Yes button. 

This Firmware version has Telnet option on Debug page.   

2. After that, perform factory reset on both  Router and the Satellite.

3. Finish basic configuration, but DO NOT connect to internet yet. 

4. Enable Telnet option on both Router and the Satellite in their Debug.html page. 

5. Telnet connect to both devices, and ran the following:

nvram set auto_upgrade_enable=0
nvram set ver_check_https_svr1=http.fw.updates1.aaa.com
nvram set ver_check_ftp_svr1=updates1.aaa.com
nvram set ver_check_ftp_svr2=updates1.aaa.com
nvram set ver_check_ftp_svr3=updates1.aaa.com
nvram set lang_check_ftp_svr=updates1.aaa.com
nvram set install_fw_upgrade_latest=0
nvram set ver_check_enable=0
nvram set ver_check_ftp_password=aaa@aaa
nvram set control_cloud_backend_fw_url=https://http.fw.updates1.aaa.com
nvram set promotion_server=updates1.aaa.com
nvram commit

6. Make sure the above run on both devices. 

7. Go to Managment page -> Advanced -> Security -> Block Sites :
     a. Keyword Block set to "Always"

     b. Add the following key words:
         http.fw.updates1.netgear.com

         updates1.netgear.com

     c. Click Apply. 

8. Perform a Soft reboot from Advanced Home : -> Reboot -> Connect back to the Internet. 

9. After that, my firmware update page showing this:

Status:

Router    RBR750        RBR750            V3.2.10.10     Service unreachable
Satellite  RBS750       Orbi Satellite-1   V3.2.10.10     Service unreachable

10, I will monitor for a day or so to see if this works.