When I initially open my prayer list... it is already "completed" and scheduled for tomorrow.
Please provide a screenshot of your Prayer List (you might find this wiki article helpful).
I have this issue if I don't close down Logos and restart it. The prayer list does not seem to notice that the day changed when Logos is constantly running. Here is another post on this: https://community.logos.com/forums/p/186273/1081153.aspx