SignalR handling disconnect

Question

I am really looking for an advice

I have a chat app and I am thinking how to handle disconnecting, the problem is the users are of two types, anonymous and with accounts. The login is when you connect first time to the app I assign a random profile then I save in the localstorage so when you comeback your profile is persistent, then registered users, well will override the anonymous profile. So when I close a tab, I refresh or close the browser, the OnDisconnectAsync gets hit and I am not persistent with the ConnectionId for any of the users at the moment. And is a problem if private chats are open between users, because ConnectionId will change on page refresh

Connections are stored in this data type

private readonly Dictionary<T, HashSet<string>> _connections = new Dictionary<T, HashSet<string>>();

I have a few ideas and I don't know which one is the best:

1. Prevent _connections.Remove(username, Context.ConnectionId); to happen, (maybe add a boolean for the status) and in OnConnectAsync look after the username in localStorage and assign corresponding connectionId
2. Store the connectionId in localStorage and assign it on connect along with the username, but here is a chance to get duplicate connectionId's that will crash the app
3. Store user profiles and connectionId in a database for registered users and anonymous users, check for an userId in localstorage and then connect with the connectionId from the database
4. Still use in memory dictionary only but query it after the username first to get the connectionId, but I am gonna run into a problem with the UI, because I generate ChatComponent and the receiver when responds it will create a second, window for private chat to the other user. So I will need to have an object that contains receiverName, senderName, and a reference to the component that is used for sending messages.
5. Maybe SignalR has a way to deal with this that I don't know and I should learn

I have been reading this post and I am still not sure because they are talking about zombie connections and I am gonna have to remove them too

I really don't have programmer friends to talk about this and all I got is litering here, I will delete the question later if is too dumb. Thank you.