I created a sligthly more complex dojo example to display the real situation i'm facing, and also please note that the issue is not related to the virtual datasource, it is not working for non virtual dropdownlist. About the example you sent, I do not need to display the value on the nearest textbox, i need to keep a recordset in sync with the dropdownlist, so here is the problem:
https://dojo.telerik.com/EbIbe/19 <- that works but, it is useless because i don't always have an actual object available at the time i'm binding the form.
https://dojo.telerik.com/Uqunic <- that don't and in my opinion it should work the same as the above, the only difference between the two is that in the first case the data has already been downloaded from the remote API at the time the form has been bound, in the second example the data is received after the form has been bound .
https://dojo.telerik.com/OyUpAw <-that is the worst: the first record still does not exist at the time we bound the form, so that is not going to work in any case.
Why does the dropdownlist act differently if at the time it were bound the bound value exists or not? What are the "dataValueField" and the "dataTextField" supposed to be here for then? What do I have to do if the bounded record is initially empty or if I receive it from the server after the form has been bound?
Note that this is not working neither when bound to a kendo datasource with a full model and schema, so I think there is something wrong either on the binding library or in the dropdownlist library.