Cannot add new SSID

[mshafirov]

I have inherited a wifi mesh system from the previous house owner and trying to configure it to my needs.
Under https://insight.netgear.com/#/wireless/wirelessOrbiSettings I can see the list of current SSIDs but I cannot add a new one nor can I remove one of the existing. I can edit some of their settings but not everything, like I cannot choose bands.

If I search for SSID like this

then it redirects me to a slightly different URL https://insight.netgear.com/#/wireless/wirelessSettings with empty list of SSID but there I can properly create and configure one (see plus button)

Unfortunately, the SSIDs I create there don't have any effect. I.e. they don't appear in any of the wifi clients.

What can be a problem?

Thank you!

[plemans]

If it was me, I'd start over and factory reset. Then reinstall from basic. If you don't have the insight subscription, you can manage it locally. MIght be the best option. 

You can find the manual and support guides here: 

https://www.netgear.com/support/product/sxk80/