[jitsi-users] Bad request when transfering calls

Hi, i’ve connected Jitsi to my Fritzbox and i can make new calls and answer
Everthing looks good, except when i try to tranfer a call to another phone.
Once i enter the new phone number and click transfer i see a message „Bad
Request“ in Jitsi and the call windows closes after a few seconds.
It takes also a while until the phone notices that the call is ended.
Any ideas what this could be?
We use another soft phone on a mac and transfering works there fine.