This is appenently supposed to be a feature…
I have commented that i would like to see an option to turn this functionality off, but currently they are deliberately replacing the “fdxx” with “ddxx” in an init.d script (i think they were using sed) based on a couple of different environment variables (current ipv6 settings, pregenerated prefix, state of some config files)
@hadmut Maybe support my request to make this optional. It has come up multiple times over the last couple of years and should really be fixed