No Parental Control RBR50 V2.7.3.22

Whats listed under Basic Tab? 
SPC will be seen under the Basic tab if and when it shows up.

You might try this on this version of FW:

https://community.netgear.com/t5/Circle-Smart-Parental-Controls/Missing-parental-controls-on-firmware-v-2-7-2-104/m-p/2069441/highlight/true#M4379

I had to do this once after accidently selecting the upgrade to SPC button incorrectly.