PowerBI Desktop - JSON table styles no longer working

[novelnova]

Where I work has just upgraded te powerBI from 2021 to Mar 2023.
The JSON theme I put together can no longer be applied to 2023 becasue it defines seperate table and MAtrix styles for "Minimal", "Bold HEader"...etc

so it used to be

"pivotTable": {
    "*": { 
         //Styles for default matrix in here
    },
    "Minimal": {
          //Styles for Minimal style in here
    },
    "BoldHeader": {
          //Styles for Bold Header style in here
    }
}

But if you apply that to May2023 you get an error saying the format is no longer valid as no additionProperties allowed. i.e you can have the items defined in teh "*" but nothing else can be defined at that level of the object.

Strangely if I open the 2021 template with the Matrix JSON applied into May2023 version and save it I can still swap and see the differnet matrix styles. 
I've looked in teh schema and no joy.
Does anyone know the new format for JSON to define Table and Matrix styles in 2023 versions.... Thank you 

[amitchandak]

@novelnova , Open an old file with this theme in the new version; and download the theme from the newer version, and use it.

[novelnova]

Thank you for the reply. I have tried that and it doesn't output the table or matrix styles in a different JSON format.