Very often (but not always) ERC data matched BOM data. (It basically always equal from big movies. For very small movies, it can be iffy whether they will even report BO to ERC or not, even if they are showing on BOM).
I would suggest checking the stock page again on Monday evening, after the weekly update to see if things are on line with BOM. I suspect perhaps some ancillary data like BO on a stock page may be a little out of whack with the changeover