We've seen this happen for a number of apps. The solution is to remove the app and reinstall it. See this post from makaiguy for detailed instructions:
How can I remove the app if it doesn’t appear in the Roku Home Screen?
Here are the instructions that worked on my Roku but also included the link to the page with the instructions:
https://community.roku.com/t5/Channels-viewing/YouTube-app-not-on-homescreen/m-p/1045683#M184193
VIA ROKU "CHANNEL INFO" SECRET SCREEN"
[Caveat: "Secret Screens" are not officially supported by Roku, may not work on all models, and may be withrawn without notice.]
CAUTION some of the items listed on the resulting Channel Info screen are required for Roku operation. Be sure you ONLY remove installed channel apps.
• Access the CHANNEL INFO screen using the remote: Home (5x), Up (2x), L, R, L, R, L
• Scroll down the channel app list to find the channel you want to remove
• Select, then Remove Channel, then Home
• Restart: Settings/System/Power <if present otherwise skip>/System restart
Thanks, I finally got it to work.
