Although other favicons are stored in the theme, Google seems to favour the favicon.ico in the public folder that displays your logo.

In fact, I have noticed this in several Shopware 6 shops in Google search results.

If you only have one public sales channel, you can simply replace the favicon.png with your own, but we have four sales channels with different favicons.

In this case, you have to set up redirects.

It would be better if the corresponding favicons of the respective shops were actually used and displayed.