Good thinking. During the fetching of the registry the “anti-malware service executable” was over 30% of CPU usage.
I added the folder .julia/registries to the exclusion list. That didn’t work.
I added .julia to the exclusion list, and then the fetching of the registries did not result in high anti-malware executable CPU usage. However when the fetching was done, the anti-malware executable went up to over 50% of CPU usage.