Backtest results will update or repaint thru the day while the current candle is being built up. Below are the scenarios that should be considered while validating results from the backtest history.
Example 1 (Single timeframe – Daily candles)
A scan running on a daily candle, the results shown at 10am will differ as compared to the results shown at 12pm and so on.. this is similar to how the indicators/candle would look for the current day on a candlestick chart i.e it will continue to change for the day until the market is closed.
Example 2 (Multiple timeframes – 5 minute and Daily candle)
The backtest history for such a scan would shown a bar for every 5 minutes(lowest timeframe in the scan), the backtest history would spread the daily candle for every 5 minutes i.e the values current spanshot of the daily candles is spread across all 5 minute bars in a day causing the results to change as the current version/snapshot of the daily candle updates.
Eg: If you view the backtest history on such a scan at 12pm and then re-check it at 3pm, the backtest bars since market opening i.e 9:15am, 9:20am and so on.. may show changed/updated results as the run at 3pm saw a newer version of the daily candle as of 3pm and backtest is generated on the fly(i.e the time you view the scan) unlike Alerts. In such a case to validate the true stocks present in a scan at 9:30am, would be to create alerts and validate the results of the alerts instead. As alerts run on the trading time (9:20am, 9:25am, 9:30am) unlike backtest, which is generated on the fly i.e when you view/open the scan page.
Note: This behaviour is NOT a bug, but rather how candlestick charts are shown/displayed, the candlestick chart show’s only the current version of the candle and not how it looked every second/minute in a day, which would mean the current candle on a candlestick chart would continue to change/update thru the day while the candle is incomplete