New project unit tests on M1Pro won't compile

I have a new SwiftUI project I'm working with on my M1Pro. The project is a simple single screen app and I selected new project app when I created it. Selecting to create unit test targets as well.

The app builds and runs. The UI tests build and run successfully.

I then attempted to create a simple unit test and run it. However it's not compiling. The apps module name is "PointsMasterII" and when try to add import PointsMasterII to the unit test, I get the error:

Could not find module 'PointsMasterII' for target 'x86_64-apple-ios-simulator'; found: arm64, arm64-apple-ios-simulator, at: /Users/derekclarkson/Library/Developer/Xcode/DerivedData/PointsMasterII-ahjymfmhybwxvxakiwljcqfzmqea/Index/Build/Products/Debug-iphonesimulator/PointsMasterII.swiftmodule

I also had this is the test class:

func testPoints() {
    let calc = Calculator()
}

And when I checked the log of the build I saw

Undefined symbols for architecture arm64:
  "type metadata accessor for PointsMasterII.Calculator", referenced from:
      Tests_iOS.CalculatorTests.testPoints() -> () in CalculatorTests.o
  "PointsMasterII.Calculator.__allocating_init() -> PointsMasterII.Calculator", referenced from:
      Tests_iOS.CalculatorTests.testPoints() -> () in CalculatorTests.o
ld: symbol(s) not found for architecture arm64

I don't know how to fix this. I would have expected it to work as the unit test target has the PointsMasterII app as a dependency (setup by Xcode) and the app and UI tests run fine.

Any pointers as to what to look at?