I'm not sure what you mean by "syndication photo library." Is it possible that you're are meaning what we call the System Library or maybe iCloud Photos?
Is it possible that you have more than one Photos Library on your Mac? You can see the Photos Libraries with the Library Chooser. To see the Chooser, close Photos and then Option-click on the Photos icon. You should get a dialog window like this:

This shows all the Libraries that Photos can find, and you can see the path to each. The one that is designated as the System Library is the one that apps and iCloud use.
A Library is designated as the System Library in Photos' Settings>General

If "Use as Photos System Library" is grayed out, then the Library is already the System Library.
Let us know if this helps with your problem, or if you need more information…