CucumberJS - cannot debug step definition code

We are using WebStorm 2017.1.2 Build #WS-171.4249.40, built on April 25, 2017.

The execution kicks off via a Gulp.js run/debug configuration. A particular gulp task is called which then kicks off the execution of the Cucumber feature files which in tern runs the Node JS code.

The issue I am facing is that the execution flow does not halts at breakpoints I apply to the code inside the JS files while running this suite.

The run/debug configuration looks like this:

When the execution is kicked off in debug mode - the console displays the following lines:

"C:\Program Files\JetBrains\WebStorm 2017.1.2\bin\runnerw.exe" "C:\Program Files\nodejs\node.exe" --debug-brk=50518 --expose_debug_as=v8debug D:\PISPAutomation_1481\ob-pisp-bdd\node_modules\gulp\bin\gulp.js --color --gulpfile D:\PISPAutomation_1481\ob-pisp-bdd\gulpfile.js pisp-api-test --ff=enquiryEnterpriseService
Debugger listening on [::]:50518
[00:10:08] Using gulpfile D:\PISPAutomation_1481\ob-pisp-bdd\gulpfile.js
[00:10:08] Starting 'pisp-api-test'...
[00:10:08] spawn wdio with these attributes:
--debug-brk=50518
--expose_debug_as=v8debug
D:\PISPAutomation_1481\ob-pisp-bdd\node_modules\core-cucumber-bdd\cuke-2017-06-14T23-10-08.849Z.tmp
read world successfully......