Fixed Play 1 unheard message staying in a Walkie Talkie conversation after the message had been heard on another device or browser tab. Pressing it said everything had been heard, but the button, the red Play button and Not heard stayed until the page was reloaded.
A message you hear on one device now shows as heard on your others within a few seconds, and pressing Play unheard always brings the page up to date. The person who sent the message is not told when you heard it.