After updating my Desktop Anki Applications I found them to differ from the AnkiWeb and ios App counts. I imagine it has something to do with certain cards in the deck being excluded. There doesn’t seem to be any discrepancy between the platforms though, as across multiple syncs there were no conflict messages or changes in the respective counts.
Recent desktop versions split the Due column into Learn and Due, but they should sum up to the same number.
I’m embarrassed to have not done the simple arithmetic but thank you.