Netgear R8000 Router setting, then setting to AP mode, then set back to Router mode

So I have my R8000 set to 10.0.x.x instead of the out of the box 192.168.x.x setting. I'm thinking of setting it to AP mode to use another 'router' that doesn't have WiFi built in. If I want to set router back to the previous 10.0.x.x setting, will that automatically happen when I turn off AP mode or will it default back to 192.168.x.x? I don't know if this previous configuration is retained in memory when in AP mode or router just reverts back to factor default 192.168. The reason for asking is I have made extensive changes in many areas and really don't want to have to redo everything if memory is lost when switching back from AP mode.

If unit defaults back to out of box configuration, will a backup of previous configuration be able to restore everything? Thanks in advance.