TCL ROKU TV no longer connecting to internet either wireless or wired after orbi RBR40 update

Hi Forum:  2 days ago there was a firmware update on my RBR40 router--not the satellites.  After rebooting, all my connected devices came back EXCEPT my 2 TCL TV's which run on the Roku platform.  Not sure if this has happened to others so I'm going to give a lot of detail here--thanks for reading!

MOST IMPORTANTLY--THE TV'S ARE ABLE TO SEE MY ORBI'S AND THE NETWORK.  THEY CANNOT, HOWEVER, CONNECT TO THE INTERNET ANYMORE EITHER WIRED OR WIRELESSLY

After trying numerous things including a factory reset on one of the TV's and even "resetting" my entire ORBI, still get the problem.  

I called Roku--they said I needed to ask my ISP (Spectrum) to change the DNS settings to either OpenDNS or Google. Spectrum cannot change the DNS settings themselves.  TCL TV's do not allow you to manually configure DNS settings (apparently my Samsung TV does).

So my question:  My current router is set to use DNS servers automatically provided by my ISP. If I change the settings (I get to do "primary, secondary, tertiary" to include either Google DNS or OpenDNS, should this solve the problem?

Also, if I change the DNS settings, will I need to "reset" (i.e. push the tiny button in the back of the router with a paperclip" my router, or simply do a reboot of the orbi network?  Thanks!