I have a Mid 2015 MacBook Pro Retina 15-inch running OSX Sierra 10.12.3 which uses the AMD Radeon R9 M370X GPU and Intel Iris Pro Graphics I'm experiencing an odd behavior I can not explain. To the hdmi port on the right side I connect a 1920x1080 hdmi monitor. To the front most thunderbolt port I connect a Monoprice Thunderbolt to HDMI active adapter which connects to another 1920x1080 hdmi monitor. To the back most thunderbolt port I cannect a LG 34UM95 via thunderbolt cable (3440x1440 resolution) This all works great! I am trying to add a 2nd LG 34UM95. If I unplug everything then To the back most thunderbolt port connect via a thunderbolt chain both LG 34UM95 monitors they both work! Plugging in the HDMI monitor on the right side port also works. But when I plug the Monoprice Thunderbolt to HDMI active adapter back into the front most thunderbolt port I get no display on that monitor. But if I disconnect the 2nd thunderbolt monitor at the end of the chain that monoprice adapter starts working again. Why is this? The only two solutions I can come up with are 1) use the Monoprice thunderbolt adapter at the end of the thunderbolt chain, but to do this I would need a $200+ intermediary thunderbolt device. https://www.reddit.com/r/apple/comments/1lsbc6/can_i_daisy_chain_an_lcd_tv_to_a_thunderbolt/ 2) Use a usb > hdmi adapter instead. But I have seen a couple that are claiming they wont work with OSX Sierra? https://www.amazon.com/Cable-Matters-SuperSpeed-currently-compatible/dp/B004MS0DIK I'm at whits end here and I'd certainly appreciate some expert insight into this little conundrum.