Time Machine not backing up a large Photos library

My Macmini has two users. The second user has a default photoslibrary and also one additional photos library file “family.photoslibrary” that time machine does not back up.  It contains over 12,000 photos and is 78GB in size.  It loads into the photos program with no issues.  I have done a disk utility first aid, and rebuild the photos file, but it is still not backed up.  There are no folder exclusions in time machine.

Time machine backs up all the several photos libraries for user 1.  For user 2 it only backs up the default library.  I also notice that the “problem” family.photos library shows the same date last opened as one in 2018 even though changes are made regularly. That date is a month before Mojave was installed.

I also tried to back it up with a trial of carbon copy cloner and it also fails to recognize and backup that one large photos library file.

Sounds more like a files problem with Mojave file system.  Any help?  I’d hate to have to export and rebuild this file.