Missing file numbers under Photos thumbnails
I just moved my photos from Aperture to Photos due to the fact that Apple unfortunately is ditching the best photos application for professional and semiprofessional photographers. The oldest photos edited with iPhoto do show the file numbers, but not the around 30 000 I imported after I started using Aperture. This is simply incredible, and Apple is getting lots of negative reactions for not supporting Aperture any more.
With this many photos, fixing it one by one by copying the number as the photo title is naturally not a solution. Working with thousands of photos without the file numbers showing up under thumbnails is impossible. With a total of 50 000+ photos and some 200 albums sorted in about 75 folders makes moving to a application where I cannot migrate my organized library out of the question. Unless the issue with Photos can be fixed, Apple is forcing me and millions of others to leave them. It beats me why they are doing this. I have been a loyal Apple user for 30 years, but they are doing their best to get rid of me.
In short, is there a simple way of getting file numbers under the Photos thumbnails?
MacBook Pro, macOS High Sierra (10.13.6), Also AppleTV