output is mumbled for a specific sentence and voice

[vcalv]

If you use the voice en_US-ryan to synthesize the sentence My general knowledge of Smith and his ideas has also benefited from numerous conversations about Smith with Don Boudreaux of George Mason and James Otteson while he was at Yeshiva University

it just mumbles almost every word after knowledge.

This is a problem with this specific voice and not any other that I've tested with, suggesting the phoneme conversion is OK.

https://github.com/rhasspy/piper/assets/66543651/bc93d4a2-85c5-4cc9-95a5-be9dd6e59594