Chart (circle) background off not working

EDIT: Add Screenshot

I am trying to use a Deneb Unit Chart (circle) from https://github.com/PBI-David/Deneb-Showcase in my Power BI Dashboard. Unfortunatelty I am not able to switch off the background of the visual. I have already tried several things. Set the background to "null" within the vegas settings, switch off the background in the Visualization properties. The background still remains with the "white" background. I am using Power BI Version: 2.138.1004.0 64-bit (November 2024) and the latest Deneb version. Thanks a lot for your help.

Code example:

{ "$schema": "https://vega.github.io/schema/vega/v5.json",
"width": 345,
"height": 345,
"padding": 15,
"background": "", --> I also tried with "null"
"signals": [ { "name": "textGradient", "update": "{gradient: 'linear', stops: [{offset: 0, color: '#036d19'}, {offset: 1, color: '#1db954'}]}" }, ...

Try:

• Switch off the background in the Power BI Visualization properties.
• Change the transparency there as well
• Removed the background coding within the Deneb visual completely
• Set the background setting within the Deneb visual to "null" or ""

Expecting: I expect that the background of the Deneb visual is transparent and I see the background from the Canvas.

Try: "background": "transparent",

EDIT: