Migrate missing photos from iCloud to Photos
I recently updated my iMac, and in the process, noticed that my Photos library hadn't added any new photos for a few weeks. The last was on August 5th. At first, I thought something had broken, but in doing a little troubleshooting, I discovered that somehow, the setting on my iPhone in Settings > Photos > Upload to My Photo Stream was turned off. Not sure how that happened as I don't think that's something I would have changed, and it gives you a warning when you turn it off about deleting photos.
If I log onto my iCloud account through a web browser, all my photos are there, but there's a few weeks worth of photos that aren't in my Photos app. What's the best way to migrate the missing photos from the server to the app? I've tried rebuilding the database, but that doesn't seem to do the trick. I suppose I could download the missing ones from the iCloud account, then import them into Photos, but that seems like a bit of a pain.
Any suggestions? Thanks.
iMac, macOS High Sierra (10.13.6)