Finalized state of the API reporting stats

I have a question when the active Taboola ads stats (clicks, impressions and spend) become stable and final.

Each day we are downloading Top Campaign Content API reports for today, yesterday, day before yesterday etc. All stats older that 4 days are cached and considered to be final. But for some campaigns it seems not to be enough and we still see some small discrepancies compared to the latest Taboola dashboard UI result. Updating the old cached stats through the API fixes the issue.

Am I wrong the stats to become stable on the 4th day?