iMac Desktop Problem

I am unable to share Desktop 1 a.k.a. “iMac”. All I get is a flickering window that says “ManyCam”.

Desktop two which is an LG monitor works fine. But I want to share the main desktop on the system. How do I get rid of the flickering “ManyCam” and get the actual desktop?

I am running the lifetime subscription that I purchased last week, running