We just joined teams but we had people outside our organization that we were chatting with through Skype for Business. I am not able to chat with them now. I was able to receive messages from them yesterday but now I'm getting an error and the person outside the organization is getting a message saying I'm not online.
I do not want to go back to Skype b/c Teams is a superior product but we need to be able to chat with companies outside our organization.
No one changed settings, I double checked them and we are all able to get external communications.
I am not sure what platform they are on. They are a large company that has "communicator" which is some sort of skype for business. I haven't had any issues chatting with them until we made the switch.