System Information
Operating system: Windows 10
Graphics card: GeForce GTX 780 Ti

Blender Version
Date: 2018-11-29 15:57
Hash: 26d5a3625ed
Branch: blender 2.80 (Beta)

Circle select not working properly

When pressing "C" to enter Circle select mode you can select with left mouse button but not de-select with middle mouse button unless you exit the select mode and re-enter it, then you can de-select with middle mouse button, this worked in 2.79b