I purchased a 2015 13" Retina Macbook Pro in May and have had a problem where when opening my computer from 'clamshell' the wifi icon shows it is connected to the internet but it is not. It also randomly drops wifi every once in a while but the indicator shows it's connected. This has been an issue in three different states on three different routers with three different ISP's. I have used Yosemite, all of the El Capitan public betas, the actual releases of El Capitan. I have trashed preferences, deleted old networks, done clean installs. I even sent the computer in and Apple pretty much replaced every part of the computer (essentially giving me a new computer) and it still does not work. Have not tried todays public beta, but will andlet you know if it fixes it. Also, installed Windows 10 on Bootcamp (which I really didn't want to do, but in the name of science...) and it does not have this problem. I'm getting really pissed off at this point and it's taking longer and longer between replies about what to do from Apple senior tech support. Apple should be paying me at this point for testing their products for them. Anybody recommend anything else to try? Thanks!