The block still works, but only with system provided sounds, e.g. from the Ringtone pick block, or by clicking the Sound URI field.
It's odd that it ever worked with regular fileUri's since the "recipient" is never granted
READ permission, there's no way to do so.
Using fileUri(soundUrl, "f") doesn't seem to work either, maybe that's the cause, Android 15 no longer supporting file:// URIs.
Probably, the only way to make this work is if fileUri could generate an URI that's publicly accessible by all apps, which is risky.
An alternative that might work is to copy the sound file into /Ringtones, that should make it a pickable ringtone.