Switches to false language and another voice for one word

[prototyperspective]

For example at this spoken Wikipedia audio at 11:15, the tool switches the voice and says it in what seems to be Spanish(?) despite that I selected English in both the input and output language and selected the en Brian voice.

This occurs roughly every 4th audio once (more likely for longer articles I guess) so it's not very rare. Another example can be heard here where the voice also switches and pronounces "formation" in French instead of English.

For the first file, the input srt file has (after linebreak) autoregressive (i.e. and in the second file it's (after linebreak) Formation (then another linebreak).

Please make sure the voice is not swapped and that the pronunciation is either always English or always English if the word exists in some English dictionary/….

[prototyperspective]

It occurs even more often and often more than once depending on the length of the audio. I don't see why whatever is used would for no reason suddenly switch the voice and the language instead of being fixed to the specified language and voice, it seems almost intentional. The voice used there and in other audios where this happened is en-US-BrianMultilingualNeural but it also occurs with other language and I think also those without Multilingual in the name. If somebody knows how this can be fixed or be worked around, please comment.