For all I know the following may apply to some desktops and/or all-in-ones, too, but I've not yet encountered it in these environments.
Since the beginning of the laptop, convention had been that the function keys across the very top of the keyboard required the Fn key that's nested along the very bottom of the keyboard to be held before hitting a given function key to make it perform whatever function the manufacturer defines for that key. Most people are familiar with function keys to do things like: volume up, volume down, mute, wireless on/off, brightness up, brightness down, etc.
There is a new feature that HP, at least, calls "Action Keys Mode" which turns this convention on its head. When activated, this makes a simple press of a given function key trigger its function rather than being passed along to whatever application as a key press. This can have some "interesting" effects for screen reader users. This function is currently enabled by default on my laptop and the F6 key so happens to be the Mute on/off toggle key. When using NVDA, if I press F6 it simply toggles the mute state. In order to make it behave as F6 normally would I must hit Fn+F6. This does not apply if the SHIFT is pressed along with F6 in order to reverse the direction. That works perfectly well. I can only imagine the chaos this could unleash if you start using the various commands that employ the function keys on a system with Action Keys Mode activated.
Action Keys Mode can be disabled, but it is controlled via UEFI/BIOS. On my machine one disables it by activating the UEFI menu by doing a repeated ESC key press during boot and selecting F10 choice. Once the old-fashioned BIOS-like screen pops up, you have to transition to the System Configuration pane and arrow to the Action Keys Mode entry and disable it. Since this is done well before the operating system is even involved, I don't know of a single screen reader that could be active to accomplish the task.
Since this mode is controlled by the hardware ahead of any intervention by anything else, you must disable it if you wish your function keys to operate "the way they always have."