Whilst investigating an issue, whereby some unit tests were failing if using "Run All" from Test Explorer, I discovered that, if run in isolation or some other subset of all, they succeeded because they were not being deployed to a new test .\Out folder (as verified in the debug Modules window).
The issue of the failing tests turned out to be a missing assembly, which I managed to resolve but my question is: why are the tests sometimes run from my common build Output path (eg. ..\bin) and not always deployed to a clean TestResults....\Out location?
[nb. I should add, the solution is not using a TestSettings file]