Hi gallina94!
to my knowledge, the problem is the dynamic token
secureTokenResponse............$9841620 6-a443-4c18-81ba-63ab11bb6675B
Sorry im not expert. But you can find more info.
http://www.hensence.com/en/coojah/rtmp_securetoken.htm
Can you show me the way of using Wireshark to get what you captured
Thanks.