I do not know if what I experience is related but, since upgrading to 2019.3, I frequenly need to restart NVDA with the CTRL+ALT+n keystroke because speech from NVDA almost grinds to a hault.

This usually happens when I'm using Firefox but what I don't know, because I'm totally blind and don't often have sighted help, is wheter Windows has ground to a halt, Firefox has or NVDA has! I do know that I didn't get this happening anywhere near as frequently before the upgrade to NVDA 2019.3.

I'm using Firefox 73.0.1 (64-bit) and Windows 10 Version 1903 (OS Build 18362.657)

Giles