Synchronising photos to my iphone in finder

Hello JM415 and welcome to Apple Support Communities.

I see you're having some issue with syncing photos between an iPhone and the finder on a Mac running Catalina.

Were the photos originally added to the iPhone using iTunes? If that is the case, then they can't be synced back to the Mac.

Transfer photos and videos from your iPhone, iPad, or iPod touch - Apple Support

"Photos and videos that you sync from your computer to your iPhone, iPad, or iPod touch using iTunes can't be imported back to your computer. "

Also note that if you are using some iCloud services, certain manual syncing options will not be available.

Use the Finder to sync your iPhone, iPad, or iPod with your computer - Apple Support

Cheers.

Yes this is ongoing issue being discusses here: https://discussions.apple.com/thread/250716707

It is either an IOS 13 problem or a Catalina problem. Photos are not syncing as they were before IOS 13/

Catalina