Resharper not running xUnit tests

The error is in my choice of Nuget packages to import.

Instead of:

<PackageReference Include="xunit.runner.console" Version="2.2.0" />

I should have had:

<PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />

You'll probably need a rebuild or turn Visual Studio off and on again after this.