While I can't answer your question, the people that might be able to help will need to know which channels you are referring to. Naturally I expect they all require some sort of authentication, but the names of the specific channels could be important.
Now, could a removal and reinstall fix it? Certainly could. To remove you use the remote to highlight the channel (don;t hit OK), then press the * button and choose uninstall. After you've done that, you must restart the Roku. Either unplug it or use the system restart option in the menu. Then install it again after the Roku has rebooted.
Nvidia Shield, Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.