I fixed it after months of not working! The NBC app has a lot of issues, including screwing up region despite the zip code entered into Roku. I’d tried the delete/reboot (not restart - settings/system/power/system reboot)/re-add/reboot to no end. I tried the same sequence, tossing in a full factory reset. Nope.
Here’s what I did. Perhaps there are extra steps but it worked for me after months of trying:
1. Home/System/Zip Code - make sure it’s accurate for your cable service (not your WiFi). We have cable at home, internet at our cabin from another local provider. I changed this to match our home cable zip code. Perhaps set it to somewhere outside of your region? NBC app has issues with the zip code because some regions (according to NBC.com) may block access.
2. Home/NBC/* - delete app
3. Home/System/Power/System restart
4. Home/Streaming Channels/NBC - add app
5. Home/System/Power/System restart
(I figured this is what Roku keeps telling us, so I did it again)
6. Start NBC App. Click up to top of screen, navigate to the right & choose More (my menu shows Home, Browse, LIVE, Networks, More, peacock, search icon).
7. Select My Profile, then TV Provider. If linked, click unlink. Choose your cable television service provider. Then authenticate through nbc.com and entering the code on your screen.
I do not know if it was the zip code in Roku or what, but when I went to My Profile on the NBC app, it showed our internet provider NOT the cable provider I have on our Roku.com account and every single other app. Whatever - it now works for me. GL!