REST API - Setting CustomProperty with Java

Using the Java example in OrionSDK-2.0.50 (App.java), I can do a query and pull info about my nodes. This works, no issues.

On one of those nodes, I have used the web dashboard to create a custom property. Now using the same App.java example but slightly modified, I'm attempting to set the value of that custom property, similar to the powershell and python examples.

My URI looks like this:

https://server63:17778/SolarWinds/InformationService/v3/Json/swis://server63/Orion/Orion.Nodes/NodeID=10/CustomProperties

My headers are set, just like App.java

I have a JSON body added, just like App.java except it is {"myprop":"GO" }

I can view the node in web and confirm the property does exist

The response is 400 Bad request

Any ideas on what I'm doing wrong?

Eclipse project is attached.

thanks for any help