The 13” MacBook Pro has a different “expected behavior” in that the screen will turn black if a second Thunderbolt Display is connected. iMac (Mid 2011 and Late 2011): Supports two Thunderbolt ...

with two and four Thunderbolt 3 ports), MacBook Pro (15-inch, 2016), MacBook Pro (Retina, 13-inch, Early 2015), iMac (21.5-inch, Late 2015), iMac (Retina 4K, 21.5-inch, Late 2015), and iMac ...