Albums shown in Finder or on AppleTV not updating when changes made in Photos?

I'm using a current model iMac with latest Catalina updates and a new iPhone 11 Pro, and an Apple TV model A1625 with tvOS 13.3. I've been working on organising my photo collection in Photos, sorting things into albums and so on.

I want to sync some folders to my iPhone. I connect the iPhone to my iMac, open Finder, select the phone, and select Photos. I check the box for "Sync photos to your device from" and choose "Photos" from the drop down list. I choose "Selected albums".

However - the list of albums that Finder offers to sync is different to the list in the Photos app. Albums I've deleted are still listed. Albums I've renamed show with their old names. Albums I've created don't show up.

If I enable "home sharing" to view my Photos library on the AppleTV (via the "computers" app) the list of albums offered appears to be the same list as I see in Finder - not the list of albums in Photos.

Restarting the Photos application or rebooting the iMac makes no difference.

I'm sure I'm missing something obvious here, but I can't see what. Any suggestions?