I installed Ubuntu Desktop (https://ubuntu.com/download/raspberry-pi) on my raspberry pi 4. I plugged in a mouse and keyboard for the installation and the setup of screen sharing. I use VNC viewer to connect to my pi through a passwort. When I connect (Windows 10 PC or Android Phone)I can control the mouse and start application from the desktop. But inside the application I cannot click anything. I can only close the windows. Same goes wirth the keyboard. I can use the e.g. the windows key, but only on desktop not inside an application. e.g. Firefox I cannot click any links nor wirte onything to the url line. When I plug in a mouse and / or keyboard the mouse and or keyboard signals from vnc viewer seem to work fine.
Any ideas how to fix this?