Delay in historical intraday candle 1 min data

I have observed that many times, the historical intraday candle data is appended with a delay.

Fo ex: I ran the script at 11:30 AM , but data was provided till 11:28AM 1 min candle, why is the data missing for 11:29 AM candle?

Is this a known issue?

@Ketan @Pradeep_Jaiswar