How to join Librewolf Matrix room?

Was wondering why no new messages turned up, since tuesday or something. Turned out the Librewolf Matrix room is changed / upgraded or something like that. It involves joining once again. But both in Element and Fluffy clients I get this error:

MatrixError: [403] You do not belong to any of the required rooms/spaces to join this room. (https://matrix-client.matrix.org/_matrix/client/v3/join/!AMixpitUKQHatikSri%3Amatrix.org?server_name=matrix.org&server_name=envs.net&server_name=fedora.im&via=matrix.org&via=envs.net&via=fedora.im)

Is there a way to join the matrix chat room one again?

I do see the space with the 3 rooms.