Weird exception when parsing form files minimal api .net 6

Question

i'm sending some pdfs trough form-data bodytype to my minimal api in .net 6 and sometimes i encounter a weird exception.

i try to read my files from the HttpRequest class like so:

HttpRequest rq
var uploads = rq.Form.Files ?? throw new BadRequestApiException();

and i get the following error:

Microsoft.AspNetCore.Server.IIS.Core.IISHttpServer: Error: Unexpected exception in >"IISHttpContext.ReadBody".

System.Threading.ThreadAbortException: System error. at System.Diagnostics.Debugger.CustomNotification(ICustomDebuggerNotification data) at System.Diagnostics.Debugger.NotifyOfCrossThreadDependencySlow() at >System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.GetStateMachineBox[TStateMach>ine](TStateMachine& stateMachine, Task1& taskField) at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.ReadBody() 'iisexpress.exe' (CoreCLR: clrhost): Loaded 'C:\Program >Files\dotnet\shared\Microsoft.NETCore.App\6.0.3\Microsoft.Win32.Registry.dll'.

However if I first read the first element of the IFormFileCollection as a Formfile and then retrive the full collection I encounter no error and data retrived is valid:

var temp = rq.Form.Files[0];
var uploads = rq.Form.Files ?? throw new BadRequestApiException();

Then I added a BindAsync method to my parsers for the IFormFileCollection like so:

public static ValueTask<IFormFileCollection> BindAsyncIFormFileCollection(HttpContext context, ParameterInfo parameter)
 => new ValueTask<IFormFileCollection>(context.Request.Form.Files);

that works fine, but upon testing my expandedBindAsyncIFormFileCollection

public static ValueTask<IFormFileCollection> BindAsyncIFormFileCollection(HttpContext context, ParameterInfo parameter) {
return context.Request.Headers.TryGetValue("Content-Type", out var type)
        ? type.FirstOrDefault().Contains("multipart/form-data")
            ? new ValueTask<IFormFileCollection>(context.Request.Form?.Files)
            : throw new BadRequestApiException()
        : throw new BadRequestApiException();
}

sometimes i still encountered the same exception (low percentage but still it happened).

Ideas greatly appriciated!!