A client hotfix has been released to correct an issue in which the game could fail to show the lobby chat and would not correctly enter lobby screens (and thus the game was unplayable without relaunching the game).
In particular, this issue would happen when the game was run outside of steam (through the app being pinned on the sidebar or launching from the game directory directly). However, this could also happen in some other cases.
Please let us know in the community discord if you are continuing to run into this issue (or are running into any other issues).