Unable to synchronise photos from iPhoto on Mac to iPhone 7plus through iTunes

[ratnagopal]

I normally store all my photos in iPhotos on Mac in Events folder. I have 50 events & 15000 photos.

I transfer my photos in camera of iPhone to Mac through iTunes and segregate them in events. Then I synchronise iPhoto to iPhone.

It was working fine till recently.

Since I upgraded to iOS 11, it is not working. I am able to transfer photos in camera of iPhone to Mac but while I attempt synchronising, they do not get transferred back to iPhone events folders

Pls help.