Additional options were added to Settings > System > Advanced system settings > Control by mobile apps > Network access.
See if taking this this out of the Limited mode solves the problem.
This is an instance where a nice little OS "Notes" overlay would come in handy when Roku pushes updates and builds/patches.
I discovered that Roku overrode previous setting and enabled 'Limited' by default causing a couple of my web-based apps to fail to interact with Roku. I was looking over settings in my computers and firewalls and by happenstance decided to look in the Roku settings to see if access was somehow disabled and found the 'Limited' enabled.
Changing to either 'Permissive' or 'Enabled' should fix this for most cases. (at least it did for me and the affected apps and desktop software.)
