4K screen, enlarge icons

Hello I searched for more than 2 hours, to find out how to enlarge the icons
but I don’t think so,

I have a new 4K screen, 3840 x 2160, and the synfig icons I don’t see them
it’s the size of an “ant”

all my computer on “linux mageia”, at a standard icon size (perfect), it’s the only software to have this problem, thanks for your help.

For the moment the only interesting discussion to find:

(as I don’t speak English, I have more difficulty finding the solution, it was probably said somewhere, thank you).