I had that same problem on my mountain bike, and it was because I didn't realize there was sort of a knack to shifting in the front. The rear is easy, and my road bike is easy, but there is kind of a sweet spot on that front shifter. My husband could shift it find but I had all kinds of trouble until I figured out that I was not holding it hard or long enough.

I have low-end Shimano components. I have wondered if upgrading might make it less of an issue, but I think it is something I can probably just work out with some practice.