P: Backup won't write to Network drive

Lightroom Classic version 12.0.1

macOS 12.6.1 (21G217)

Upon quitting, Lr Classic asks to save a backup. If the backup is saved to a local drive, it succeeds. If it is set to save to a network drive (NAS) it fails.

1. Open Lightroom Classic

2. Quit Lightroom Classic, click Yes to really Quit

3. In the Back Up Catalog dialog select a network drive, Test integrity and Optimize can be checked or unchecked, click "Back up" button

4. Backup Up Catalog window appears with "Copying catalog" progress bar, it changes to "Compressing catalog backup"

5. Errror message appears, "Lightroom was unable to back up the catalog named "CatalogFilename". Please check your folder permissions, and make sure that you have available space on your backup drive and main catalog's drive.

6. Choose a local backup drive and it works

This was working in version 12.0, but would sometimes crash after saving. Now it doesn't crash, but it won't write. I tried unchecking and rechecking Full Disk Access in Security & Privacy for Lr Classic. No change. Error message attached.