sidecar issues

Hello Chris_dust,

Welcome to Apple Support Communities!

We want to help you get the most from Sidecar with your devices.

Check here to help isolate the source of the issue:

"Get ready

• Before continuing, make sure that your Mac and iPad meet the Sidecar system requirements, including that each is signed with the same Apple ID.
• You can use Sidecar wirelessly, but to keep your iPad charged during use, connect it directly to your Mac with the USB charge cable that came with your iPad."

Then verify yoru settings:

"Change settings

To find Sidecar settings:

• macOS Ventura or later: Choose Apple menu  > System Settings, click Displays in the sidebar, then click your iPad at the top of the window.
• macOS Monterey: Choose Apple menu  > System Preferences, then click Displays. Click Display Settings, then click your iPad in the sidebar.
• Earlier versions of macOS: Choose Apple menu  > System Preferences, then click Sidecar.

These settings are available only on computers that support Sidecar:

• Show Sidebar: Show the sidebar on the left or right side of your iPad screen, or turn it off.
• Show Touch Bar: Show the Touch Bar on the bottom or top of your iPad screen, or turn it off.
• Enable double tap on Apple Pencil: Allow apps that support this feature to perform custom actions when you double-tap on the side of your Apple Pencil (2nd generation)."

This Apple Support page has the full details: Use an iPad as a second display for a Mac - Apple Support

If the issue continues, do you see any error messages when the issue happens? Does a normal restart of both devices have any impact? We hope this helps.

Cheers!