Retaining old text-to-speech voices alongside the new neural voices

I have the same problem. I have tried all of the following to no avail:

• deleted the TTS audio and recreated it using notes
• deleted the TTS audio and recreated it using text from a Word document
• deleted the TTS audio and recreated it by manually retyping the entire thing
• deleted the offending phrase/paragraph and manually typed it in
• removed all punctuation including parentheses which at first seemed to be the problem
• deleted the phrase/paragraph from the TTS script and recreated it as a separate audio file
• numerous variations on making the above changes and then saving the file and closing/reopening Storyline

None of these have worked and we now have to send the project to the client with audio in which the voice changes mid-stream for no apparent reason. If you were not going to make the old voices available, could you not have removed ALL of the old coding to prevent this from happening??

UPDATE: After Support Chat, I was told this is a "known bug." In my experience, that means we will not see a fix to the switching voices until they push out an update to fix it. Good luck explaining that to your clients. ~sigh~