Missing text after certain phrases (Charles de Gaulle)

iOS & iPadOS
We have discovered that VO and Siri fail to read several words after the phrase Charles de Gaulle! This is reproducible on all our iPhones (approx. 12) except for one iPhone 4s. For example: Charles de Gaulle won't be read. This reads as just 'Charles de Gaulle'. This probably sounds like a practical joke if you're reading this using VO, but I can assure you it is real. Has anyone got any other examples of this happening? Or know if a Radar has been filed already? Thanks, Alex