Noticed after updating to FW 4.19 that I wasn't receiving the audio "voice" alerts on my phone when laps occurred, then on my run this morning I had my headphones connected listening to music and no "voice" lap alert there either (just an audible beep).
So I dove into my settings and noticed that the Lap Alert setting was toggled OFF. I can only guess that the new FW reset this option?
Not a big issue, just posting in case any one else uses voice alerts and want to doublecheck your settings.