After re-entering My conference room on demo-server I meet quite another interface with not working widgets and whiteboard

In My conference room in FF browser I've:

1. uploaded document to the whiteboard and highlighted some content
2. wrote a post for my colleagues. Then occasionally quited the room.

And after re-entering I saw a strange picture:

1. no content on the whiteboard
2. monotoneous blue coloured chat with no content, enlarged to the 2/3 of room space thus diminished the whiteboard space to minimum size.

After entering the same room in Chrome browser I saw another strange picture

1. whiteboard shifted to participants sidepane
2. chat shifted to the bottom and became horizontal bar
3. no tools sidepane for whiteboard. Video-window didn't appear at all.

The same behavior was observed yesterday. Bug is persistent.