I had a bit of trouble getting driving instructions to show.
In the same way that Pro Maps is a bit fussy about how the default address is entered when you just want to display a map, it also has to be able to exactly recognise the address that is entered as a starting point in the driving directions.
If it doesn't recognise and identify that location precisely, there isn't even a grid or outline to show that driving instructions should appear.
Try experimenting a bit with the details of the address, post code, county etc.
No idea why it isn't working on a PowerStore page, though. What do you get? Is the page completely blank, do you get any error messages, or is there just a gap where you'd expect the map to be?
Can you see the expected code in the live page's source view?