Syncing tones using Apple Devices app on Windows 11

Apologies if this is not in quite the right place, but since there doesn't seem to be a category for the Devices app on Windows, I figured iTunes would be the closest one.

Previously, I have used iTunes to add custom ringtones to my iPhone. For example, by recording my own as an M4A file, changing the extension to M4R, and then dragging that file onto my iPhone in iTunes to add it.

I have tried this same procedure on the Devices app in Windows 11, but it does not seem to work. It adds the tone(s) to the Tones tab under my iPhone in the app, but they do not show up in Settings on my iPhone (even after syncing). The normal syncs work normally, in that I can add and remove music just fine. It's only the tones that seem to not want to sync. I can still see and use tones I have added in the past, before I started using the new app, as long as I don't delete them.

Is this functionality not yet fully working in the new Devices app? Or has Apple decided to drop support for this for some reason?