Hi
Test mode will match at the best available price recorded by the program.
For example:
in the attached screenshot the trigger fires in a lay on the fav at a price of 20.00.
it is matched at the best available price which is 8.40
you can also see the last traded price on the selection is 6.60
I think in the example you give, the price of 1.50 was not available long enough for the program to register it within your set refresh rate. If you check the trigger log, it should give you information as to why your trigger did not fire.