Block Services not allowing more than 1 IP

Trying to use the block services feature to block my kids devices at night so they cannot sit up on the internet all night.  I can add one local IP to the block services table, but any others I try adding it will let me enter all the info but when I  click add it just goes back to the device table with the first IP I entered as the only entry.   When I  try to add a service to block I do the following:

Click  Add+ from the Block Services screen

Under Service Type I change this to ALL.

Under Filter Services  For I select Only This IP Address and enter the IP I wish to add.

Click Add+

Why cant I add more than 1 IP to this?  Netgear  phone support will not assist unless I pay since I got the router free from my ISP 60 days ago.  They tell me my ISP should be helping me with it.  ISP has no clue and resorted to googling the same information I had already found on the Netgear site.  How can I use the Block Services feature of this router for multiple devices?