I use Citrix and VNC on Win 10 to connect to my Mac at work, and I find I can't type the # symbol. I have a UK keyboard, so shift+3 produces £ (both remotely and locally), and the key marked # produces 3 on the remote machine.
No other combination of Shift or Alt or AltGr or Ctrl and 3 produces # (Alt+3, AltGr+3 and Ctrl+3 on my Windows keyboard produce nothing but the Citrix beep)
Switching keyboard layouts to US switches the £ for # locally but not remotely.
Is there another way to produce #?