System Information
Operating system: macOS 10.14.6 (18G95)
Graphics card: Radeon RX Vega 64 8 GB
Blender Version
Broken: 2.81, 2.81a, 2.82 (2019-12-05 e2806b7429c7)
Short description of error
Once I pressed a modifier key (alt ⌥, cmd ⌘, ctrl ⌃, shift ⇧) shift keeps locked.
For example: On launch [A} select everything. After pressing [alt ⌥], pressing [A] opens the Add-menu.
After tabbing into another Window [⌘] + [⇥] and back to blender everything works fine until I press a modifier key again.
Looks like DonMarron on blenderartists.org has the same issue: https://blenderartists.org/t/modifier-keys-bug-blender-2-81-on-mac/1192127