Recently, while using my rMBP Late 2013 15 inch, my bluetooth keyboard will disconnect. I'm using an external monitor with the lid closed (nothing else plugged in except power and monitor). I want to say that this started after updating to 10.10.4. I have to remove the keyboard and readd it and it gives me trouble doing that but eventually works. I changed the keyboard batteries so that is not an issue. Is this a known issue in 10.10.4? Any ideas? Thanks!