Why isn't "Path to project(s)" modifiable?

Question

In an Azure DevOps build, a .NET Core Test step has a "Path to project(s)" property, which is set to **/*[Tt]ests/*.csproj.

Why can't I change it?

Answer 1

It's editable if one manually adds a .NET Core build step to a build switched to the "Test" command instead of using the "Test" step from the default .NET Core sequence of build steps.