The problem has existed for a long time, icons for elements with music are not displayed.
If you look, then in Russian an undenfined error appears in the console.
buttonImg.src = this.getSoundIcon(category);

Here are some examples. English language.

That's it in Russian.

(These are pictures from the beta version.)

The problem was that if you enable another language on the site (for example, Russian), then the options values were taken with a translation in the selected language. They didn't match the category values (in English) in icons.jres.

1. Therefore, I decided to change it so that options sorting is disabled so that options do not change places in different languages.

2. Next, I from the initially obtained values
   soundIconCache = JSON.parse(pxtTargetBundle.bundledpkgs['music']['icons.jres']);

I recycle the object so that all elements are with indices
soundIconCacheArray = Object.entries(soundIconCache);

I remove the first element from my array, it is not needed. Interferes.
soundIconCacheArray.shift();

3. In the refreshOptions function, I first get all the categories.
   const categories = this.getCategories(options);
   Then I look up the index in the array with all the categories of the category element
   const categoryIndex = categories.indexOf(category);

Further, to set the picture for the musical element, I pass this index to getSoundIcon.
buttonImg.src = this.getSoundIcon(categoryIndex);

4. I rewrote the getSoundIcon function itself so that it takes an icon from my earlier soundIconCacheArray by index.

I checked in several languages. The changes are working.
As a result, we get this...