How to reproduce:
1. Open the attached project "1185630.zip"
2. Open the Test Scene
3. Enter Play mode
4. Press Add data button multiple times

Expected result: Console logs numbers in a sequence adding one number after each button press
Actual result: Console sometimes writes random numbers (usually 1s and 0s) after some button presses

Reproducible with: 2018.4.14f1, 2020.1.0a16

Notes:
Unity Collections package is not available on Unity 2017.4, therefore the issue is not reproducible.
Could not reproduce using Nvidia graphics card drivers 431.60, however, the issue reproduced after updating to the latest 441.66 version.