It's not just channels.
Tom Clancy's Jack Ryan isn't a channel. It's Amazon. I saw issue there.
KidJoe
Turns out i had 10 download credits left...
Like i said, my US downloads machine's v6.1.8.2 was acting up so i used Total Uninstall (unregistered 30-day trial version) to remove StreamFab and i deleted the DVDFAb folder from my %AppData%\Roaming folder.
I then installed v6.1.8.3. For my Canadian machine i had done an Uninstall with Revo maybe 2-3 weeks ago. My v6.1.8.2 was fine so i just did a regular upgrade with the 6.1.8.3 offline installer.

Episodes 1 & 2 are 1080p H265 from PrimeVideo Canada
Episodes 3 & 4 are 1080p H265 from Amazon US
Episode 5 is 720p H265 from Amazon US
Episode 6 is 480p H264 from Amazon US