I'm currently in BRC and can't log back in on this toon because I'm getting disconnected constantly. We engage the first boss and as soon as he does the chain move we all disconnect and log back in dead, but it keeps disconnecting once you log in.
Take look at this thread, it seems very similar to what is happening to us. Unfortunately Blizz doesn't seem to have a fix for this yet & despite the thread being 11 pages, we still haven't gotten a blue response. Some of us have tickets in with Blizz tech support, but, so far none of what they told us to do alleviates the problem. It feels like we are getting the run-around. This is awful & Blizz should be ashamed of themselves.
I'm having the same issue with Rom'ogg Bonecrusher soon he cast ability Chains of Woe full party disconnects.