[Theory]
[MemberData(nameof(GetMemberDataContext))]
public void ValidParameters_Success(int param1, int param2)
{
	// Arrange
	Mock.SetupStatic(typeof(MyClass), Behavior.Strict, StaticConstructor.Mocked);
        Mock.Arrange(() => MyClass.method1()).Returns(true);

        // Act
	IService service = new Service();
	bool result = service.method2();

	// Assert
	Assert.True(result);
	Mock.Assert(() => MyClass.method1(), Occurs.Once()); // <-- the test fails here because it reports that method invocation occurs twice
}

The issue in not observed if the code is modified in the following way, which indicates behavioral incinsistency:

[Theory]
[MemberData(nameof(GetMemberDataContext))]
public void ValidParameters_Success(int param1, int param2)
{
	// Arrange
	Mock.SetupStatic(typeof(MyClass), Behavior.Strict, StaticConstructor.Mocked);
        Mock.Arrange(() => MyClass.method1()).Returns(true).OccursOnce();

        // Act
	IService service = new Service();
	bool result = service.method2();

	// Assert
	Assert.True(result);
	Mock.Assert<MyClass>();
}