Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
Maybe try the typical Uninstall, System Restart, and then reinstall of the MLB app/Channel.
You can also try updating the channel with the *button, and then doing a System Restart.
Sometimes when I install a channel on one Roku, it doesn't always behave correctly on another until I either update the app or do a Setting...System..System Update (this updates both system OS and channels). I always follow with a System Restart.