@CarolZiemba
Although it does say Seasons 3 and 4 are available on the Roku Channel, there does appear to be a server issue with error "No Providers Found".
You can watch Seasons 3 and 4 of Sanctuary on these other other free channels/apps available on Roku.
Freevee, Plex, Tubi, Pluto (verified to be working).
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102