For others with problems with the Mormon Channel for Roku, try simply removing the channel and restarting your device.
I just did that on my Roku TV. For now, at least, that did the trick. Not sure why, since that device was brand new. I guess maybe there is some cached data stored at the Roku server level that cleared when I removed and restarted.
Just checked the old Roku 1, as well, and it is streaming better now.