Random green lines displaying on screen share

I have green lines/boxes showing up randomly during screen sharing.

I have turned off “Show Green border around my shared content”, and I have disabled “Use hardware acceleration for video sharing.” This did not solve the problem.

It is not consistent, and I cannot readily replicate it. The lines come and go randomly. I am sharing a Lightroom Library, and the lines show up as horizontal lines that extend across most of the screen with some vertical lines at the edge to form open boxes. I’d guess the lines are about 10 pixels thick. They are not in alignment with the picture grid or any underlying borders/boundariesin Lightroom.
I have the latest OS and app software as of September 2026. I am running on a Mac Studio, sharing with one remote colleague. 

I’ll try to get a screenshot next time it happens