Trouble with French gels

[Beautybumblebee]

Hi
For some bizarre reason my French Gels are not lasting any where near as long as my block colour gels. I do base coat then two coats of pink and then my white tips followed but the top coat. I always cap the edges and my prep is exactly the same as when I do block colours?
I have had 3 customers now tell me it's chipped within a week.

What am I doing wrong?

I use nail harmony or Gelaze

Thanks

 

[pure]

I use Shellac and apply base coat, 1 x pink, 1 x white French and 2 x top coat. I've found the second top coat stops chipping issues.