How can I connect my Samsung tv to 5 GHz band for streaming?

Netgear C7000v2 installed with Xfinity Internet, and all Apple and Google devices can login to 2.4 & 5 Ghz bands.  When I try to enter the password for my Xfinity WiFi into Samsung QTQ8D settings, the TV does not let me complete the full password and I'm in xfinity unsecured and not able to stream in my individual secure WiFi account.

Does anyone have recommendations?  Thanks for your time & help!