niRFSG (PXI5670) control: Setting attribute Direct download error= IVI: Invalid value for parameter property

Hi I have been using your grpc server (https://github.com/ni/grpc-device) to control a signal generator using python and that's where this issue started.  According to documentation "For the PXI-5670, direct download is always disabled. For all other devices, direct download is always enabled." we need to set the Direct Download attribute before sending out waveform.  Fine, we can set any other attribute no problem so this shouldn't be an issue either, however when it comes to the `Direct_Download` attribute we get an error saying :

errorcode:-1074135024
Exception: Error: IVI: Invalid value for parameter or property.

 so I tried a sample labwindows/cvi program for the nirfsg named "ArbitraryWaveformFromTextFile" from "C:/Users/Public/Public Documents/National Instruments/CVI/samples/niRFSG/ArbitraryWaveforms/WaveformFromTextFile"  because it attempts to set the same attribute in a different manner/language what have you, however we get the same issue:

IVI: Invalid value for parameter property

Property: NIRFSG_ATTR_DIRECT_DOWNLOAD
Valid Values: NIRFSG_VAL_DISBALE

I have attached a screenshot for your convenience.

I original posted to ni/the grpc-device github repo however this appears to be a deeper issue and not necessarily related with that repository and so I am posting here.  Not sure if its in the right section so if it isn't can you please let me know/move it to the correct location.

 Thank you for your help.