I can’t seem to figure out why the review heatmap is different on the Main/Deck screen versus the Stats screen. Some of the days have different review numbers as well. When I downloaded the Backfill addon and also tried manually to turn back time and review a card and Check Database after, there was no change. Please let me know. Thank you!
The calendar depends on your “new day start time” which you can change in the settings. Maybe the addon uses 12:00 AM and the app uses 4:00 AM or something. If the addon has an option to change its own new day start time, that would be better.
Is the displayed stats calendar for the whole collection and not for a particular deck?
The primary difference is that those are 2 separate things, and only one of them is produced by the Review Heatmap add-on. What you see on Stats > Calendar is a built-in part of Anki, so the settings you use for the add-on (month-by-month, color, inclusions/exclusions, etc.) don’t affect it.