Operating system: mac OS Mojave 10.14.4
Graphics card: Radeon Pro 580 8 GB (external) , Internal Radeon Pro 4 GB
Broken: (example: 2.80 2019-04-23, Hash : 40baa2e2b358, as found on the splash screen)
Short description of error
Happens only with recent build, when using Blender 2.80 on the external screen connected via HDMI through Blackmagic eGPU Radeon Pro 580 8 GB, when switch to edit mode, i cannot select any Vertex, face or edge, when window is move to internal display select in edit mode works properly, tested with blender 2.79 it works regardless of internal or external display.
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).