Ventura and iPad OS 16.3 Have Broken Sidecar
Brand new, 2023 M2 MacBook Pro 16" (clean install of macOS 13.2 Ventura) and 12.9" iPad Pro (3rd Gen) running iPad OS 16.3.
Sidecar does not work at all even with the USB-C connection. I can move a window to the iPad but within a few seconds it moves back to the Mac and the iPad goes back to the Lock Screen.
I tried signing in/out of iCloud - did not fix the issue.
Under the Ventura Displays settings for the iPad Pro, I turned off the "Linked keyboard and mouse" and set it to "Extended display". That has made it a LITTLE MORE reliable, but I still get random disconnects whenever I try to move the mouse between screens.
Maybe my "solution" helps others, hopefully Apple is working on a fix.
MacBook Pro 16″, macOS 13.2