I've created a simple Radzen application with only a grid component and an OData external service. While creating this application I discovered Radzen is using an HTTP PATCH method to update resoure:
Indeed Radzen applications use PATCH to update records. It is possible to use PUT but you will have to change the implementation of the put method in client\src\app\odata-client.ts and include that file in Radzen's code generation ignore list.