Cant create unique app launcher per activity in plasma 5.8 in debian stable

[aprekates <aprekates@posteo.net>]

in plasm 5.8 LTS used in debian stable i create a plasma widget and i 
put firefox (A) in it. I do the same in   another activity (B). Now if i 
try to change the command line in firefox A the same change will happen 
to B.

I want each activity to have its own custom firefox icon.

Alexandros