OK, I tried a new 'TBR' Catalog.
While I did not see your issue, I did see another 'quirk'
in Library Metadata:
Author1&Author2
Author2&Author1 (author 2 is now the
Prime Author in a series)
Author1
The Authors sort in the catalog Flips the order when needed. but... you get
Author1
Author1&Author2
Author1&Author2 <<