With Tickstory 1.7.4, the spread is equal to zero every time.
The solution is to launch first a test with "Control points", then stop it immediately.
The spread will now be taken into consideration. You can launch a test with the "every tick" mode.
You have to repeat this operation every time you change the spread. Otherwise the spread will remain the same.
Source : https://tickstory.com/articles/ticks...-7-4-released/
You can also downgrade to a previous MT4 build version like MT4 build 910.