So I can access the photos and develop them, but the metadata has been disturbed.
What do you mean by "disturbed"? Be very specific and detailed so we can understand exactly what the problem is.
Did you at any time during or after this transfer of Lightroom import the photos into Lightroom?
Thanks very much for your quick response. In answer to your first question, it says "Changed on disk" for the Metadata Status of photos in the Macintosh HD /Users.........../Master (14543 photos). In the section Volumes/Macintosh1......../Pictures (4654 photos) it says "Up to date"
The only photos I have imported into Lightroom since the transfer are some that I took yesterday. As far as I recall, the application is accessing the photos in the photolibrary which has not been moved. All my photos are on iCloud. And they all show in Photos.
Is that helpful?
So if you look at the metadata for these photos in Lightroom, does it appear correct, or not?