I have posted one like this before but with the sun it this morning, it looks like a real forest of grass.
Thank you for all your suggestions and commiserations about Catalina yesterday. If I had had the courage of my convictions, I would have solved this problem very quickly. All it needed was the computer shut down and restarted and all was well. I was afraid to do that with an update but I do it all the time when things get hung up!