BS Responsive grid not working?

I've followed everything to a T so far in this tutorial

but the BS grid isn't RESPONDING and the features list won't stack. I've looked at the code of both my own and the demo version given in the youtube video description side by side and lets just say apart from a bit've dryer CSS on the demo version, my own styles are what has been show to do here and still I've got this problem! As far as I understand all responsiveness is supposed to built in so I shouldn't need to go fiddle with or try tweek anything..?

Any feedback would be much appreciated thanks.

of course you have to do some work with the responsiveness!!!

First you have to know how Bootstrap works. the Demo is in Bootstrap3. If you make your own Design... now Bootstrap4 is used.

So learn how to use Bootstrap4, or use the old version 3.

THEN you can perfectly use Bootstrap Studio to make your responsiveness.

Bootstrap Studio is a tool to make your work more comfortable, but you have to know what you will do.

You have to publish some code, or design which is not working like you want

Ok I see. I've hardly ever used BS I've tried staying clear of frameworks till I have the fundamentals down. I figured this program would be just what I need to have that balance of code and visual to learn faster. As for whichever version of BS, the vid tut is a tad misleading then for the uninitiated who don't know the difference, and how the instructor even says at 12:45 mins in "Thanks to the BS grid the features list is now fully responsive and adapts to the page width" and thats it no demonstration of setting the media queries or anything. I don't mind figuring out and learning for myself but its a bit frustrating I'm sure you can understand, but thanks again for the response I figured I wouldn't get one anytime soon its been a big help, cheers.