[SOLVED] AutoSetUpConfiguredDrivers occasionally throws an 'Index out of range" Exception

Here's the content of my GlobalSetup - occasionally when I run, the call to AutoSetUpConfiguredDrivers throws an exception:

System.ArgumentOutOfRangeException: 'Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')'

        EdgeOptions Options = new EdgeOptions();
            Options.AddArgument("window-size=1600,900");
            Options.AcceptInsecureCertificates = true;

        EdgeOptions HeadlessOptions = new EdgeOptions();
            HeadlessOptions.AddArgument("headless");
            HeadlessOptions.AddArgument("window-size=1600,900");
            HeadlessOptions.AcceptInsecureCertificates = true;

        AtataContext.GlobalConfiguration
            .UseChrome().WithArguments("ignore-certificate-errors", "window-size=1600,900")
            .UseChrome().WithArguments("ignore-certificate-errors", "window-size=1600,900", "headless").WithAlias("chrome-headless")
            .UseFirefox().WithGlobalCapability("acceptInsecureCerts", true).WithArguments("--width=1600").WithArguments("--height=900")
            .UseFirefox().WithGlobalCapability("acceptInsecureCerts", true).WithArguments("--width=1600").WithArguments("--height=900").WithArguments("--headless").WithAlias("firefox-headless")
            .UseEdge().WithOptions(Options)
            .UseEdge().WithOptions(HeadlessOptions).WithAlias("edge-headless")
            .UseCulture("en-US")
            .AddScreenshotFileSaving()
            .UseNUnitTestName()
            .UseNUnitTestSuiteName()
            .UseNUnitTestSuiteType()
            .UseNUnitAssertionExceptionType()
            .UseNUnitAggregateAssertionStrategy()
            .UseNUnitWarningReportStrategy()
            .AddNUnitTestContextLogging()
                .WithMinLevel(LogLevel.Info)
                .WithoutSectionFinish()
            .LogNUnitError()
            .TakeScreenshotOnNUnitError("Test Failure")
            .OnCleanUpAddArtifactsToNUnitTestContext();            

        //DriverSetup.AutoSetUp(BrowserNames.Edge);
        AtataContext.GlobalConfiguration.AutoSetUpConfiguredDrivers();

If I uncomment the DriverSetup line, I never see the error. Using Atata 1.13.0, Atata.WebDriverSetup 1.2.0 and Selenium 4.0.0 - any ideas?

--As requested - here's the stack trace:

at System.ThrowHelper.ThrowArgumentOutOfRange_IndexException()
   at System.Collections.Generic.List`1.RemoveAt(Int32 index)
   at System.Collections.Generic.List`1.Remove(T item)
   at Atata.WebDriverSetup.DriverSetupConfigurationBuilder.SetUp()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj)
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Atata.WebDriverSetup.DriverSetupConfigurationBuilder.<SetUpAsync>d__11.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Atata.WebDriverSetup.DriverSetup.<AutoSetUpAsync>d__26.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Atata.WebDriverSetup.DriverSetup.<AutoSetUpAsync>d__28.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Atata.WebDriverSetup.DriverSetup.<AutoSetUpSafelyAsync>d__30.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Atata.WebDriverSetup.DriverSetup.AutoSetUpSafely(IEnumerable`1 browserNames)
   at Atata.MethodInfoExtensions.InvokeStaticAsLambda(MethodInfo method, Object[] args)
   at Atata.AtataContextBuilder.InvokeAutoSetUpSafelyMethodOfDriverSetup(IEnumerable`1 browserNames)
   at Atata.AtataContextBuilder.AutoSetUpConfiguredDrivers()
   at Atata.Config.SetUpFixture.GlobalSetUp() in C:\Source\fs.automation\Atata.Config\Atata.Config\SetUpFixture.cs:line 45