OS: Windows 10 Professional 64 bit
CPU: Xeon E3-1231 v3
GPU: GTX 1070 8GB Strix
Blender Version 2.81 Master (11-22-2019)
Issue: the After pressing the A-Key to select all, it must be pressed again (sometimes several times repeatedly) before deselection will activate.
Note: Seems to be working fine in 2.82 alpha version.
