Does the issue only occur on the Willow app or across other channels installed on your Roku stick?
If you haven't tried yet, you can remove the affected channel and then re-install it. To ensure the process is successful, restart your device before adding the channel back in. We would recommend doing this from the Settings menu by navigating to Settings > System > Power (If you do not see a Power submenu, skip to the next step.) > System restart.