update_stream_deck_widget not working

Hello,
I'm on the latest alpha and tried all possible combinations but update_stream_deck_widget seems not to be working for me.

I have a script widget that has no js, just for a test, but it's there and it's visible.
Then from a standard Stream Deck button I have a 'run real javascript' action like this:

(async () => {

  let uuid= 'C0000D61-5A2A-4C14-9D0D-018C47F956A7'
  let widgetConfig = {
    text: "some new title!",
    BTTStreamDeckBackgroundColor: "200,100,100,255",
    BTTStreamDeckSFSymbolName: "bitcoinsign.circle.fill",

  };

  update_stream_deck_widget({uuid: uuid, json: JSON.stringify(widgetConfig)});
  returnToBTT(result);})();

But it does nothing. I have double checked the uuid and tried several other tests, including creating new widgets for tests and using this version of the fn:

callBTT('update_stream_deck_widget', { uuid: uuid, json: JSON.stringify(widgetConfig) });

but the result is the same, that is, nothing happens.
Is there a way I can debug this?