Scene flythrough mode doesn't work while holding shift

Steps to Repro:
1. Open the attached project or create a new project
2. Go to scene view
3. Right-click + Hold shift + Now Use WASD to navigate around scene view

Actual result:
Observe that the flythrough mode doesn't work

Expected Result:
While holding shift accelerated flythrough mode should work

Workaround:
1. Go to scene view
2. Right-click + Hold navigation keys 'WASD' + Now hold shift
3. Observe that the flythrough mode is working

Occurring with:
2018.2.0a7, 2018.2.0a6

Working with:
2018.2.0a5, 2018.2.0a1, 2018.1.0b13

Environment:
Windows 10, OSX 10.3