History disappeared when updating Lightroom

Have same problem as many others. All history disappeared when uppdating to the latest version of Lightroom on Windows 10. I am a professional photographer, and I am using two catalog files. One big and one smaller. Updated both.

From the bigger, and most important one, I lost all history. The name of the updated catalog file is "Lightroom Catalog-2-2-v13-5.lrcat". The version of the updated Lightroom is "14.3.1 release".

The catalog prior to the update was 27.2 GB. Ater the update it is 2.31 GB. The size of the lrcat-data file is now 429 MB. Prior to the update it was 470 MB.

I have copied the "Old Lightroom Catalogs" folder to another place, as well as the newly created catalog files. Then I copied the two old back and restarted Lightroom by clicking on the catalog file. It updated to a new catalog, still called "...v13-5.lrcat", 2.31 GB in size, and without history. What should I do now???

When I updated the smaller catalog, it kept the history, but also kept the name "....v13-5.lrcat" Is that OK?

Best regards,

/Desperate