Sidecar not working with MacOS Sequoia and iPadOS 15.6

In the beginning sidecar works, which is to say that I can choose the iPad as an extended screen and I'm able to move pages or applications from the computer to it by using window and move to iPad. The problem arises when I try to move the cursor from the computer to the iPad: it automatically switches from extended screen to duplicate mouse and keyboard, so it comes back to the normal screen of the ipad simply not communicating with the computer. I've already checked and I'm running Mac OS sequoia 15 and IOS 15.6.

Can you help me?

[Re-Titled by Moderator]