All available channels can be accessed online at the Roku Channel Store (https://channelstore.roku.com)
The Roku Media Player is here (https://channelstore.roku.com/details/1829ae20b082957f963d7dab42abf7e5/roku-media-player)
Any added channel is always added to end of the list on Home Screen. Press Home a few times, then press your Up arrow once to scroll up and quickly go to end of list.
Normally performing a manual system update (which updates the OS and all channels simulataneously) will work, followed by a System Restart. (Settings/System/System Update and then Settings/System/Restart or Settings/System/Power/Restart depending on device).
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660x, Premiere+ 3921, Express 4k+ 3941