How to reproduce:
1. Create a new Unity project
2. Press Ctrl+B

Expected result: the "Build and Run" command is executed
Actual result: nothing happens

Reproducible with: 2018.3.0a6, 2018.3.0b2, 2019.1.0a1
Not reproducible with: 2018.2.9f1, 2018.3.0a5

Notes:
The issue might take a few attempts to occur
The issue reproduces both on Windows and MacOS
It was not possible to force a build on MacOS prior to 2018.3.0a6 using Control+B, only Command+B
On MacOS the hotkey doesn't work every second time Control+B is pressed. On Windows, it seems to be much more random