It has been a full year since my initial post.
Still happening. Roku_Reps - at your convenience - you can stop posting the same canned information (aka "Have you tried turning off and on again?")
Apparently there is some billing snafu where the cached / stored information on the Roku device doesn't match the billing database on the provider side, so it just 'locks'.
One way to test it is to try and log in on https://www.watchhallmarktv.com/ - if your login is working there, it ain't Hallmark. Its the interaction between Hallmark and Roku services.
It will usually resolve itself for a week or so after you jump through enough time consuming hoops, but the issue is clearly not important enough to resolve quickly (say .. in under a year, for example).