HELP! Problem moving library from older Mac to newer Mac

I have a catalog that I have been working on in Sequoia on a Macbook Pro. I had to send that machine in for service.

So I copied the library folder to an old iMac running Ventura. I moved the image directory (which is on an external drive) to the old iMac.

I then worked for a few days on that iMac.

When the Macbook Pro was returned, I copied the libary folder back from the iMac to the Macbook Pro. I reconnected the image directory to the MacBook Pro.

Unfortunately, when I opened the library on the Macbook Pro, many of the edits I made are not there when I reopen the library on the Macbook Pro.

Adobe support has suggested:

• rebuild all smart previews before backing up the older library
• backup the library on the older computer and open that backup on the new computer

Neither of those worked.

I even turned off syncing, just in case some of the online images were retrieving old settings from the cloud.

It's bizarre. Even though the library is exactly the same from one computer to the other, when it opens, it's different.

Where it really shows up is in color labeling. The images that I applied color labels to on the older computer do not have those color labels turned on when I move to the newer computer.

Has anyone encountered this? Have you fixed it somehow?