Tablet doesn't share screen

Hi. I've installed quick support on my android tablet, so I can control it with my windows10 pc. I'm able to connect the two, but I cannot see the screen of the tablet. What I get is the picture sent in attachment. I can see information from the tablet (battery, etc), but not the screen. And therefore, control it like I want. Can you help me solve this matter? Thanks in advance.

tablet doesn't share screen.PNG