When I published my channel the feed was being automaticlly reingested (~every 6 hours) and that worked for about a month. Now it's completely stopped and I don't know why. There was no notification that it stopped, nor was there any error messages...
Something similar happened to my channel a while ago (a couple months) and interacting with support I found out that when they installed my channel automatic feed updates were working fine.
The only thing I could think of to do was UNINSTALL the channel, reboot the Roku device, and REINSTALL the channel again. That actually worked!
So I then had to make an instructional video to put at the top of my channel listing telling people with the channel already installed to do that same uninstall, reboot, and reinstall if they found the feed wasn't being updated anymore. . . .