Can't use menus/launch apps - Connected via local wifi and over the public IP

Hi! I am very happy I can connect to a headless Pi 4 on my home WIFI network and using the public IP address using the Android app and the Windows 10 app. I can move the mouse, open folders etc, interact with the VNC menu options, transfer files - but I am unable to open the Raspberry Pi menu with the mouse or windows key. Any tips or what to search for or pointers very much appreciated.