How do I fix Sidecar stability issues on iMac and MacBook Pro?

I have tried rebooting both computers and I have tried both Wireless and wired connections. Both have the same result. It will connect and function then after a few seconds it'll drop the connection on the MacBook Pro. I used it flawlessly for the past year but now I have these issues. I can't find anything I'm doing different.

[Re-Titled by Moderator]