Thanks JayJayD for the heads up.
I have logged the prices of last_close, yesterday_daily_close, first_minute_close and first_minute_open. I wanted to check if the prices are correct. I have also modified one_minute_after_open_market to 5 minutes (instead of 1 minute). Looking at the log results for the date 2017-09-06, I dont understand the following:
1) If the schedule is 5 minutes after market open then first_minute_close/open prices should be at the time of 9:34? As I understand RollingWindow value (self.minute_rw[1].Close and self.minute_rw[1].Open) are with index [1] so it should be one minute prior current. But the log result shows the prices at 9:31 (I am referring not to the time stamp of the log but to the time of the price occurance)
2) the prices are a bit off with my source (tradingview.com) at prices on 9:31am:
first_minute_close - (tradingview) 162.72; (log) 162.77
I have checked other dates as well and there is always some difference of +-3-5 cents. Is it due to different databases used by both platforms and therefore there can be time discrepencies of setting minute bars?
3) As I understand QC uses pre-market closing prices (not previous trading day's closing price) which is what I need. However, after numerous backtests with different stocks the logs always show me the price of yesterday_daily_close which is two days old. In the backtest attached the result of Pr day close on 09.06 is $164.04. But on the nasdaq website (as per screenshot) this (similar) closing price only occurs on 09.01 $164.05. Shouldn't the closing price be of the date 09.05 $162.08 as self.daily_rw[1].Close is at index [1]? Even If I change it to [0] I get a price of $161.47 which does not even match any closing price at any date.

I apologise if these questions are due to my lack of basic knowledge of programming but I tried researching for answers but there are not many sources that would explain simple concepts in python in QC context. Therefore, this is my last resort (as far as I know) to get my answers so I really appreciate anyones' input and help. Thank you!