Dear Adrian,
I have problem with cross compile FLTK application on my host PC.
https://community.toradex.com/t/how-to-cross-compile-fltk-application-in-toradex-version-2-8-lts-and-newer/16104/2
As I can see you also use Toradex V2.8 version could you please share your fltk-config file or how you succeed to compile fltk gui.
kind regards,
Klemen