I have a Dell P2715Q 4K display connected to my new Thunderbolt 3 Docking Station (TBT3-UD1-83) using the a DisplayPort to mini-DisplayPort cable, connected to a mini-DisplayPort to TB3 adapter plugged into one of the two TB3 ports on the TB3 Docking Station.
The Docking Station is then connected to my mid-2017 15" MacBook Pro.
I also have a Dell U2410 that is connected to the dock using an HDMI cable and the included HDMI to DisplayPort adapter and then plugged into the DisplayPort port on the dock.
Additionally I have a Pluggable Super-SuperSpeed 7-Port USB 3.0 Hub (USB3-HUB7-81X) connected via the TB3 dock’s rear USB-A port.
With no identifiable pattern, my 4K display connected via the TB3 port on the docking station seems to disconnect and reconnect (basically it goes black, and then a few moments later, comes back on). The MacBook doesn’t seem to recognize it as a disconnect since it only the one display goes black, the builtin display and my 1080P display stay lit.
Wondering what could be wrong. Using the 4K display (using the same adapters) directly connected to the MBP doesn’t experience this problem.