It's important not to overthink certain aspects of markets and trading. Flags work, until they don't, and then price can violently turn the other way around, or even peter out and slowly sneak by!
Think of the markets as a slow
EEG-meter. The patterns are self-similar, but the reasons and dynamics behind them varies all the time.
Volume is an independent variable of price. If you follow a volume-price timeseries, notice one thing: Notice how volume and price movements varies, from swing to swing. This tells you, there are varying forces at play, at each pivot low / high.
The truth is simply this: Price does what it does. Whatever happened before, might happen again, until it doesn't! Instead of focusing on one pattern: flags. It is beneficial to widen the perspective also, to the background and repeating patterns over longer time. Instead of assuming something works 100% or someone is repeating the same actions again and again like a dumb machine, one need to embrace the ever-changing nature of the markets, and see if one can make sense of it somehow. Best bet is if you can test hypothesises and quantify their results.
It's hard to know what is what without more information. What may work in one instrument may work differently in another.
Instead of expecting to find a simple solution that solves the entire puzzle, expect to find little pieces, scattered here and there. If you manage to put them together in an intelligent and responsive way, you have a fighting chance.
UPDATE:
Prices where buyers and sellers meet over time
Supply and demand over time
"It varies"
No hard "rules"
The simple rules lead to complex questions (ie. like Chess or Go).
If none of the above satisfy, maybe this will bring satisfaction (and ruin):
The whitespace beyond pricebars is where the institutions keep their stops..