BINGO!

And follow the directions in order and don't just start with the setting the low limit screw either. Examine carefully the position of the derailleur on the seat post before doing anything else.

Every adjustment that you make to a front derailleur affects the subsequent adjustments. Usually, when somebody brings a front derailleur to me that isn't working, it's had one misadjustment piled onto another misadjustment trying to compensate for something basic that's wrong.

I do quite a bit of work for tandem owners and for road bike people who don't race. I've had a good amount of experience setting up STI triples. They work fine as long as you're not cross chaining stupidly.