I already look around, but
- Im not able to boot from HDD
- I cant save my config changes after reboot
I must be missing something important?
That sounds like you are running OPNsense in live mode. At the console, when you get the login prompt, instead of logging in as root try logging in as install. Same password.
Bart...
Yes, I just realized it few seconds ago, after reading over and over again the link:
https://opnsense.org/users/get-started/
and
https://docs.opnsense.org/manual/install.html