I’m not sure who fixed it, or when, but somebody resolved the issue involving Firefox in Windows 10 laptops from HP and other manufacturers who use the Conexant audio hardware and software. What happened in my 2017 laptop was that running the Firefox browser would cause a Conexant program called Flow.exe to start using a whole lot of CPU, causing the laptop to run hot – and poorly. The “fix” at the time was to rename the Flow.
The problem for users of Windows laptops using the Conexant audio driver that makes Conexant’s Flow.exe program eat large amounts of CPU when the Firefox web browser is running has not been solved by “conventional” means. And in order to be part of the “solution,” should one ever come, I filed a bug with Mozilla on the issue. There have been many fixes proposed for this problem, which only seems to manifest itself on my HP Envy laptop while running Firefox.