Starting a few days ago, whenever I open any chat room, all chat history is not available. Even if somebody pings me in a room, I click on it to open it up and it just says "Let's get the conversation started". This is for the Windows 10 app (Version 1.0). Everything works great in the mobile app.

Private chat is working fine - I can see chat history in there. It's just not in any rooms that I can see anything.