thank you for sharing your question with the Wefugees Community.
Unfortunately, you are not allowed to renew or to get your national passport with your refugee protection. Not only you are not allowed to visit your country's embassy but also you are not allowed to get the protection of your country of origin. So, even when you apply online for your national passport and get it or renew it, it means that you get the protection of your country of origin. That is why, you lose your protection in Germany.
For More information, you can go to the following link and read Section 72 Subsection 1 of the Asylum Act of Germany: https://***.gesetze-im-internet.de/englisch_asylvfg/englisch_asylvfg.html
In addition, for more information about a blue passport and to which countries you are allowed to travel to, you can go to the following link and watch the video about it: https://***.youtube.***/watch?v=q0VbbgfFYfw
I hope, I could have answer your question. I am a MBEON consultant. If you wish to contact me directly, you can have a **** at my profile and follow the instruction there.