Dual Band Wifi Management

Hello, 

I have tried many a time to split the bands of my wifi into 2.4 and 5g signals. However, whenever I make this adjustment in the admin tool (10.0.01) I don't see the changes that I've made reflected in our network, even after I have diligently saved my settings in admin and restarting our gateway XB3. I have assigned separate SSIDs for each frequency and assigned different passwords for each. I've tried band splitting in both the xfinity app and the online admin tool But still all I see is the original network name. This is especially frustrating because I have been unable to connect certain smart devices to my network on account of only the 5g signal being broadcast. Please let me know how I can fix this issue.