Hi, I am Dave, I will help you with this.
The actions associated to the function keys (F1 - F12) are controlled by the PC manufacturer, not by Windows, because those actions vary from PC to PC, so it is a utility installed by the HP that controls them and that probably needs to be re-installed.
Turn on the PC and repeatedly press the esc key to open the HP Startup Menu.
Press F10 key to open BIOS.
Select Advanced menu - System Options.
Toggle the Launch Hotkeys without Fn Keypress setting to its opposite setting
Save that setting and restart your PC and check if that solves the problem.