Dear @Chubby,
Welcome back at Wefugees and thank you for reaching out to us again. I can understand that you are a little nervous. But it's almost impossible for me to say from a distance and without knowing your case what the reason is for inviting you back for a third interview. Did you get the impression that the interviewer did not believe your story or your reasons for fleeing and that they now want to go into any ambiguities again?
I recommend that you seek advice from a counselling centre (preferably an asylum procedure counselling centre/"Asylverfahrensberatung"). The counselling staff can also contact the BAMF, for example, to find out more. They can also support you in the preparation for the interview. Would you like to share with us exactly what the invitation to the interview says (without giving any personal details, of course)?
Looking forward to your response and I wish you all the best,
Meike