The chatroom window is left of the board. You can see on this screenshot where chessless_1 (me) asks the opponent if he is still there.

I made this screenshot using microsoft edge. The chatroom window does not appear in Opera.
Using Opera I can play on lichess but cannot communicate which is very sad!

While playing there should be a window to chat with the opponent beside the chess board. It is there in other browsers (i tried Edge).
I tried all the settings including reset, cancelled all extensions but nothing worked.
Can anybody help?