Speech Settings STOP Button Doesn't Stop Speaking (Test) Voice

Version: Beta (845700) 64-bit - 24 Feb 2020

I am using Amazon Polly voices on my computer. Scrivener sees them!! However, when I go to test them in the Speech settings, the STOP button does not stop the voice, though it does gray out the dialogue box, so it registers the button click.

UPDATE: After the voice was through speaking, it then showed “STOPPED” in the dialogue box.

UPDATE: It doesn’t stop for real in the main text either.