photostream no longer works with iPhoto on iMac

I still use iPhotos on my iMac because my older TiVo can stream photos to my TV only from the iPhones app (TiVo cannot do this with the Photos app).

Just recently (since Feb. 2), photos I’ve taken on my iPhone 6S still appear in iCloud, but they no longer download to my iPhotos app on my iMac. This may have happened after I applied the iOS update 11.2.6 shortly after Feb 2, with Apple perhaps changing some settings that I’ve since tried to restore. I’ve been searching the web since and cannot find an answer.

Here are my iMac and iPhone details.

iMac iPhotos preferences - My Photo Stream, Automatic Import and Automatic Upload are all checked. (Photo Sharing is not checked).

iMac iCloud preferences - the Photos (it says Photos, not iPhotos) preference has a minus sign in the box (which I think is different than just having nothing in the checkbox). Under Options in the iCloud Photos preference, iCloud Photo Library is NOT checked, but My Photo Stream and iCloud Photo Sharing are all checked.

iMac mid 2010 machine running Sierra 10.12.6 (I haven’t gone to the latest OS because I have an old grading program I use for teaching my high school classes and I’m afraid it won’t run after Apple changed everything).

I am using the latest version of iPhoto on my iMac

iPhone 6S with latest iOS, 11.2.6

In Settings/[user name]/iCloud preferences:

Photos = on

iCloud Photo Library = on

Download and Keep Originals is checked

Upload to My Photo Stream = on

Upload Burst Photos = off

iCloud Photo Sharing = on

Any advice would be so greatly appreciated!

Thanks,