Hello,
Could you try on a non-US stock to see if it works?
If it does : this mean that the US data feed you have through Binck to ProRealTime is missing that data, therefor you will not be able to have it on US stocks .
Otherwise, you should send a report of you platform to be in contact with ProRealTime directly.
You can do that with the shortcut ( Ctrl + M )
Have a good day!