Changes to REST API in Videobridge2

I successfully use JVB v1 as a standalone service controlled by REST Api. Currently I would like to upgrade to version 2. Creating conferences and updating via REST seem to work as expected and I did not notice any breaking changes here. But most important part does not work: the webrtc connection is not established between a chrome peer and jvb.

There are some differences in the logs between v1 and v2, but the most probably reason is missing ufrag, which makes the connection fail immediately:

2020-10-19 10:54:27.515 WARNING: [50] [confId=79b45462469f810f epId=teacher::1 local_ufrag=funld1el012553 gid=-1 ufrag=funld1el012553] Agent.generateLocalUserName#1060: Remote ufrag of IceMediaStream with name stream-teacher::1 is null!
2020-10-19 10:54:27.516 INFO: [50] [confId=79b45462469f810f epId=teacher::1 local_ufrag=funld1el012553 gid=-1 ufrag=funld1el012553] ConnectivityCheckClient$PaceMaker.run#922: Pair failed: 192.168.0.17:10000/udp/host -> 192.168.0.17:65066/udp/host (stream-teacher::1.RTP)

Any help or tips are highly appreciated. Thank you.