The TestUnlockReleaseNextSynchronously test is unstable

[jeromelaban]

I'm submitting a...

• Bug report

Current behavior

Running TestUnlockReleaseNextSynchronously on the CI fails randomly

Environment

Nuget Package: 

Package Version(s): 

Affected platform(s):
- [ ] iOS
- [ ] Android
- [ ] WebAssembly
- [ ] Windows
- [ ] Build tasks

Visual Studio
- [ ] 2017 (version: )
- [ ] 2017 Preview (version: )
- [ ] for Mac (version: )

Relevant plugins
- [ ] Resharper (version: )