I tested the HMN app and its loading on all my devices (8 different models).
When reinstalling an app, you MUST RESTART the Roku before re-adding the app:
1) Remove Hallmark Movies Now app
2) RESTART the Roku
3) Reinstall Hallmark Movies Now app
(If you dont restart the Roku, app settings (including any bad/corrupt ones) remain behind and are "added back" when the app is reinstalled)