Why does Captivate become unresponsive when adding slide notes via Speech Management window?

Adobe Captivate 2017: 10.0.0.192

MacBook Pro late 2013. macOS Sierra: 10.12.5

For some reason, every time I try to add slide notes using the Speech Management window, and then either save or generate speech, Captivate becomes unresponsive. The only way I can get it to work is if I add slide notes from the Slide Notes panel, then check all the slide notes for TTS, and open the Speech Management window to generate speech.

It seems like a bug because it consistently happens every time I try adding slide notes from the Speech Management window itself.