Photos app does not sync up to date

[Jackypat]

For a long time my iMac has not synced my Photos. They are fine on my MacBook Air but I need the iMac to store the many photos I have. I have rebooted many times, I have created a new photos library. Also when I open the app it takes hours and hours restoring from iCloud, which slows down everything else. when complete it only restores to a date several months ago

 

[Vudor0817]

Maybe you can use an external hard drive and copy the photo's you synced from the macbook air and then copy it to the iMac

 

[hg.wells]

How are you syncing your photos to your other devices?

You mentioned creating a new photo library on your iMac which could potentially be the issue. iCloud will only sync to one photos library on your iMac, if you created a secondary library it may not be defined as the primary photos library.

 

[Vudor0817]

That might be a better solution...

 

[hg.wells]

This article runs you through the process of designating the system library:

Designate a System Photo Library in Photos - Apple Support

If you have multiple photo libraries on your Mac, you can choose which library to use with iCloud Photos and Shared Albums.

support.apple.com