thanks,
I did some further research and it turns out that Vodafone, my provider, seems to only allow bridge mode if you use their own modem/router combo for all available options / your own modem/router for a specific data tarif. Wich I do not have. I'm gonna have to call them and ask if I can even do that with my current fritzbox or If I'll have to get another device from them or some other option