Firefox was having a hard time connecting to Google docs, sheets, and slides, saying "Connecting" or "Reconnecting." Then whenever a connection was established it was very slow, it couldn't keep up with everyone else on the doc, and the connection would drop constantly. Now I've resolved this by going to Options > Advanced > Network > (Connection) Settings... > No Proxy This has fixed the issue for now but it's unclear how effective it's going to be with other users on the doc because I haven't had sufficient time to test it all out yet. I made this post to help others find this solution because there's nothing online that directly relates to solving this problem with Firefox. I hope it helps. Adam