External monitor freezes and iPad locks when using Sidecar on Mac mini M4

I am experiencing an issue when trying to use Sidecar between my Mac mini M4 and my iPad Pro 2019. When I activate Sidecar, my external monitor freezes, and my iPad locks without properly mirroring the screen.

I have tried the following troubleshooting steps:

• Ensured both devices are updated to the latest versions of macOS and iPadOS.
• Restarted both devices.
• Checked the settings under "Displays" in System Preferences on my Mac.
• Tried both wireless and wired connections between my Mac and iPad.

Despite these attempts, the issue persists, and I am unable to use Sidecar effectively. Could you please provide assistance on how to resolve this issue?

[Re-Titled by Moderator]