I would like to add that their might be a bug with the LinkOS Zebra Forms API. I use my own implementation of the LinkOS Zebra Forms API and the implementation found in the demo sample found here Getting Started with Link-OS Multiplatform SDK both throw the same exception. This is only for the ZQ520 and tried on two different ZQ520 and both did not print. The ZD410 prints perfectly. Exception is thrown when trying to check the printer status.

​Is it possible if ya can try printing to a ZQ520 using the demo sample found in Xamarin component store: Getting Started with Link-OS Multiplatform SDK with out any errors?

Stack Trace
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in :0
  at Java.Interop.JniEnvironment+InstanceMethods.CallObjectMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniMethodInfo method) [0x00068] in :0
  at Android.Runtime.JNIEnv.CallObjectMethod (System.IntPtr jobject, System.IntPtr jmethod) [0x0000e] in :0
  at Zebra.Sdk.Printer.Internal.ZebraPrinterZpl.get_CurrentStatus () [0x0003d] in C:\repos\xamarin-sdk\Binding Libraries\ZSDK_ANDROIDX\ZSDK_ANDROIDX\obj\Release\generated\src\Zebra.Sdk.Printer.Internal.ZebraPrinterZpl.cs:152
  at LinkOS.Plugin.ZebraPrinterImplementation.get_CurrentStatus () [0x00005] in C:\repos\xamarin-sdk\Link_OS_SDK_for_Xamarin_Portable\LinkOS\LinkOS.Plugin.Android\ZebraPrinterImplementation.cs:29
  at MyProject.PreCheckPrinterStatus (LinkOS.Plugin.Abstractions.IConnection connection) [0x0000e] in /MyProject/ZebraPrinter.cs:153
  --- End of managed Zebra.Sdk.Comm.ConnectionException stack trace ---
com.zebra.sdk.comm.ConnectionException: Malformed status response - unable to determine printer status
at com.zebra.sdk.printer.internal.PrinterStatusZpl.getPrinterStatus(Unknown Source)
at com.zebra.sdk.printer.internal.PrinterStatusZpl.updateStatus(Unknown Source)
at com.zebra.sdk.printer.PrinterStatus.getStatusFromPrinter(Unknown Source)
at com.zebra.sdk.printer.PrinterStatus.(Unknown Source)
at com.zebra.sdk.printer.internal.PrinterStatusZpl.(Unknown Source)
at com.zebra.sdk.printer.internal.ZebraPrinterZpl.getCurrentStatus(Unknown Source)
at mono.java.lang.RunnableImplementor.n_run(Native Method)
at mono.java.lang.RunnableImplementor.run(RunnableImplementor.java:30)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5034)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
at dalvik.system.NativeStart.main(Native Method)