UWP BluetoothRfcoom DataReader "The operation identifier is not invalid”

I'm conneting to a device with bluetooth (UWP application) and during the connectionstate I'm available to read the data I want. However when the connection phase is complete, I'm running calls to the device every 250ms from a System.Timer from my .NET standard project.

When I do this, depening on how i create the DataWriter and DataReader (static or foreach call) I either hang forever or get:

"The operation identifier is not valid".

await dataReader.LoadAsync(Convert.ToUInt32(size));
dataReader.ReadBytes(buffer);

I have tested to run the application in a singlethreaded UWP application where it works fine. Is there any way around this? Feels like its Xamarin.

Otherwise would I need to re-write the entire functionallity for this. We are doing a cross-plattform (Xamarin) where the customer also want an UWP application to run on their Windows Tablet.