I'm playing version 1.14 and it appears that F3+H or FN+F3+H won't show me the durability of my items anymore. I've been playing Minecraft for many years, did they remove the ability to see Durability in 1.14?
It still works for me consistently. Try pressing
F3 + Q to see the command list, and if it is changed, it should show up there. Otherwise, just make sure your
H keys work independently, and if nothing's wrong there and the list still says to use
F3 + H, then make sure your system isn't treating
F3 + H as a shortcut to something else (not sure why it would unless you made it do that...).
Otherwise, try loading another version and seeing if it works there; if not, either your keyboard is broken, your computer is overriding or not receiving the shortcut, or something else system-related (try checking your cords), and if so, try reinstalling 1.14.