Update: Joplin eventually finished syncing on my Mac , and later on my other devices as I did them one at a time.
The file lock errors may have been due to the size of the initial sync , which was 2.5GB of files. I think the file count was around 72k, about 42k of markdown files, and 30k of resource files such as images and pdfs.
The app is working great now that I’m over until initial synchronization hurdle. Thx for taking a look at it .